Best exercise program on recumbent exercise bike for someone with physical ailments

I'm a 50 yr old obese woman with osteoarthritis in my right knee and plantar fibroma in my left foot as well as chronic problems with my hips and back.  I bought myself a recumbent exercise bike and have been riding it 5 days a week for 30 mins a day or 10 miles (whichever takes me longer). I've been using the easiest level for the whole ride and I do get my heart rate up, getting myself in a sweat every time.   Researching best recumbent exercise weight loss programs all I've been able to find is ones geared to people in good physical health. I'm looking for advice on the best way to get the most out of my bike ride without causing my physical problems any more harm.  Anyone out there who can advise me?

I also have a recumbent bike & an upright bike. The only thing I can think of for the bike is to either increase your speed/resistence, but I'm not sure if that will aggravate your body more. You can try to switch it up, like maybe go faster for shorter amounts of time. 

I like to listen to music on the bike & I made a playlist so that I could ride/walk to the beat of the music, like a fast song comes on I speed up, a slow song I slow down. It keeps my body guessing.

Try working out your arms too, it's one of the good things about working out on an exercise bike, look ma no hands! LOL You can lift one of those little 1 or 3 pound weights, or just lift your arms above your head, to the side, to the front,curls, etc, etc.

Again I don't know if this will help, maybe try doing a modified version of whatever exercises you found & make it for you.

Thank you for your help.  I am too much of a multi-tasker to just sit and watch tv so I watch my favorite shows while I ride (just finished season 5 of Bones).  I put the tablet over the bike panel so I can't see how long or how far I've ridden and it helps keep distracted so I don't peak lol.  The weights is a good idea.  I'll have to see about getting some light ones.  

Instead of investing in weights you can use unopened soup cans, etc.