I'm still happy as a clam but I don't exercise

I've lost about 215 lbs without doing any exercise.  Now I'm feeling a lot bette and want to begin to exercise.  My problem is that I quickly became exhaurted and then get physically ill.  This has happened to me twice in the past 2 weeks.  I can't walk very far with a cane, so I take my rollator (a walker with wheels and a seat) and I'll walk for 50 to 100 ft and then sit down and take a breeak.  I may get in a total of 300 ft accumulated walking.  Then I pack up and drive home.  I'm so tired that I lie down and can't get up.   I end up sore and unable to even get up to urinate--I can't even find my portable urinal.  I end up not eating my evening meanls and don't take my evening mends.  When I finally get up about 12 hourse later, I'm still sore but able to start cleaning up.

Waht should I do?  I guess the only solution is to start out wifh even shorter distances.  Ii go with my camera but I son't have to go too far into parkds since I bring my binoculars wit me.  I can just go to the parks and not exercise, but I'm starting to feel adventurous.  It's just that gettingsick and sor is a real dragI

Ya know, I have followed your post for awhile and this post is much different then previous posts.
Maybe a long sit down with your PCP or WLS surgern is needed.
Individual mobility is a key to average heath let alone good heath and struggling with bi-polar meds can result in the tail wagging the dog.  I had a wife who had the same problem.  Her meds were changing like an hour hand.  
Using a treadmill may help - easier to pace and you can get off.

I know that my bi-polar meds are stable and doing their job.  However, mobility is a major problem  I now weigh 356 but it's not distributed evenly.  De to lymphedema, my right leg weighs about 60 lbs more that my left one.  After I got sick Yesterday, my wife said she thinks I should see my physician.  I haven't seen my surgeon in over 4 years.  I do get along well with my primary, so I will contact him.  I thank you for your concern.  I knew that was a strange posting and somewhat embarrassing, but I wanted to be honest and to and to get some help.