I have gained 50 pounds and its makes me mad and depressed...

First off, I would start journaling  and weighing everything you eat and drink. Get a good idea of how many calories you really are consuming. You may be surprised or not. I know I was. Grazing a little too much and not drinking enough I found out by journaling = regain!

Maybe between your health issues and medications,  is 1800 calories is too much?

Medications can cause weight gain. Also have your thyroid checked. Plus we are 5 years older and our metabolism so are different than they used to be. At least for me and these crazy hormone changes.

maybe find another type of exercise of you can to change things up a bit. 

Good luck. Regain sucks.

First of all you did awesome losing so much before, but I don't blame you for being scared of the regain...  I just pulled a calorie counter and threw in some random average estimates at this link calorie-calculator.  1800 calories daily definitely won't help you lose the 50 excess lbs you said you wanted to, and even may be too much to maintain, especially like you said if you are taking in meds and that may cause weight gain.  Try to measure your portions and maybe set a daily calorie limit that's a little lower... 

Good luck as you try to recover your losses!!!

Thanks for the link to the calorie calculator. 

Regain is the pits.  I've regained about 12 lbs. and working to take them off.  I am retired but work for a temp service part time.  The current assignment has been a 7 month job.  My last day is Friday.  Sitting on my rump 5 days a week hasn't help me lose any weight.  When I get home I don't exercise.  Next week I'm going to gym plus when I'm home during the day I'm much more active.

You got great info from other posters so I won't repeat.  My meals are still small and I'll be 7 years out in July.  I found I was grazing and even though it was healthy food it was too much.  I try to eat about every 3 hours.  I plan my food for the day dividing it into 5 meals.  I use Sparkpeople.com.  For me, 1800 calories a day would turn me into a roly-poly woman.  Unless you are extremely active, which with all your medical issues you can't be, I would say that's way too many calories.  Do you eat a lot of carbs?  Carbs are not our friend.

Good luck to you!

Get an accurate scale and use it every morning.  Forget the fad diets and learn to weigh and measure your portions and track calories accurately.  A goal of losing one pound a week for the next year will get you back to where you want to be.  Trying short cuts will just make it longer and harder.

Cutting 500 calories a day will result in a one pound loss in a week.  Exercise really does not matter much for weight loss.  It is taking in less than you burn and counting calories is what does matter.  I weigh myself every single morning and always know exactly what I weigh and whether I have gained or lost weight the day before.

My Fitness Pal is the best tracking app I have ever used.  Also buy yourself a Fitbit or other tracker.  Make your health your priority.  Baked, broiled and grilled foods have calories.  You have to be aware of how much of them you are eating.  The truth is that you could lose weight just eating potatoes and cookies if you kept the calorie count low enough.

The magic is not in the type of food, it is in the amount. 

I wish I could hit the like button 20 times for this.

You have already taken the hardest step by saying enough is enough and now I want to get back on track.  Here are some steps I hope will help you. They helped me...  Also, be sure and join the Back On Track Together group link in my signature area.  

Planning/Preparing

Remember when we were preparing for surgery?  How many meetings, classes and such did we attend?  We were told the more prepared we were the better our chances were for success.  And they were right. Go through the house, car and work place and get rid of trigger foods.  Stock up on foods that will keep you on track. I removed every carb/sugar temptation and replaced it with lots of protein, veggies and fruits.  

Journaling

Get back to journaling.  This will help you identify when you feel like eating, stress factors and any triggers in your life.  Once you identify these factors, this will help you put tools in place to keep you from eating.  It became clear I was not taking time for me anymore. I worked my day job and then spent the rest of my time caring for my husband.  It was easy to reach for fast, prepackaged food.  Since I purged my home I have to eat clean as there are no other options LOL

Use a tool to track you're eating and exercise like Getting Started with Health Tracker

Once I started to track ever bite and drink it became clear why I had gained.

Goals/Rewards

Make a list of goals for yourself.  Make them realistic and small.  Some of mine were move more, purge all junk from my home, eat more protein.

Food

In general, a long term post-weight loss surgery eating plan includes foods that are high in protein, and low in fat, fiber, calories, and sugar. Important vitamins and minerals are provided as supplements. (if you had a different surgery adjust this to your food plan)

Water

Water is our Best Friend. I have to say I never went back to pop or any bad drinks, however I was drinking tea like crazy. What is wrong with drinking tea?  I was either using sugar or 3 equals and 3 sweet n lows per 32 ounce glass.  So I was either pushing to be diabetic or get cancer.  I found once I started carrying a bottle of water around 24/7 (yes had one at my bedside) I lost the cravings for the sugar and I KNOW those artificial sweeteners are not good for me. Look I am old and if you add up all the artificial sweeteners I have consumed I am sure I am at the rat in the lab getting cancer threshold

MOVE!

I can't say enough about how key this was for me. The reason I kept my weight off for almost 10 years was no matter what I kept moving.  If I could not go to the gym I would walk. I loved Zumba, bootcamp workouts, lift weights. When I stopped, the weight came on.  So for me I am starting slow to avoid injury by walking and using some of the workouts on my Demand TV.  Find something you love to do and it won't feel like a pain in the *** to do daily.

Support

If it's an option "run" don't walk to a support group.

Keep me posted on how you are doing

Do you still need protein shakes 5 years later? 1800 calories is way too much. Sorry