Looking for some help please

I have looked many places for information to help me and am kind of hitting a wall. I am going to run down what has happened to me real fast and post where I am at. Any suggestions made I of course will speak to my doctors about so feel free to speak up. First I was diagnosed with Ulcerative Colitis when I turned 20. Over years things got worse and I was very limited on the foods I could eat safely and most of the time I ignored that. UC is a genetic disease that triggers in early 20s or early 60s most of the time. My father had is trigger 2 years after my UC almost killed me in his early 60s. During my battle with UC I had doctor totally miss a DVT and threw a couple of blood clots to the lungs. Survived that with no longer term damage. My UC worsened and I had to have my large intestine totally removed. After the surgery of my large intestine removal I woke up with no pain medication screaming because the pharmacy sent the wrong pain meds and I was not allowed to be given those. I passed out from shock. After that I have been forced to live with an ilostemy. I worked out and was doing well on my recovery over 2 years and then I sneezed and my intestines burst through my abs and twisted in a knot forcing another emergency surgery. The hospital messed up again, but at least I had some pain meds in my system just too low a dose and it felt like my chest was on fire when I woke up, and then passed out again from pain. After this PTSD and panic attacks set in. I sought mental help, but have found just finally began to recover from all of this in the last few months (after years of looking for the right therapy). Then the chest pains began 23 days ago. During this time of depression, fear and panic, I shut myself away and became extremely sedentary. I shot up to 375 lbs on a 5'7 male frame. The chest pains concerned me and so should have my weight, no excuses I just did not care anymore, I had given up. 2 years ago I had a stress test on my heart and I was fine, but in those 2 years I gained 100lbs and at my 375 lb weight I had a new stress test done. The ejection fraction of blood pumped out of my heart is now around 47%. From my research and doctors they say 50-65% is normal, but it is how you feel. I feel like crap and have a hard time moving or even getting up. I can only stand for about 2-3 mins and my heart is pounding in my chest (the ER did tests and said I have not had a heart attack). The cardiologist has put me on multiple medications to reduce the stress on my heart and done an echo on my heart, that looked good, but the ejection fraction is still low at 47%. I was told to take my meds and change my lifestyle, with no other information. From the research I have done I need to lose weight and exercise, which is an obvious answer. Being able to stand for 2- 3 mins before feeling like I am going to pass out and cannot breath means adapting to new forms of exercise. Going up and down stairs and treadmills are out of the question for me right now. Barely getting out of bed is stressful. I have been trying to just move / lift my arms and legs using their own weight while laying down (just started today). My heart seemed to handle this ok without chest pain. I am attempting stretching exercises to loosen the muscles as they spasm and cramp very easily. The muscles in my chest cramp so bad it takes valium / muscle relaxers to get them to release otherwise I feel like I cannot breath. I have been to the ER 3 times for this in the last month. Diet is cleaned up completely. Everything is low sodium. I am focused on fish, lean meats in proper portions, veggies, some fruits, limited dairy. I have lost 15 lbs so far and now weight 360 lbs. My chest still hurts every day, but I am unsure of what the pain is. Is it just muscles and a build up of lactic acid over a long period of non use and muscle shorteiing due to sedentary life, am I having real chest pains, or is it all in my head from the PTSD and how I now react to doctors and medical situations? (I am not really asking for an answer to this as I know no one can give me a straight one safely.)

ACTUAL QUESTION: What low impact exercises are good for morbidly obese people while sitting or laying down. I was considering using very light weights and trying to do leg raises in a seated position as well as working my arms and stretching my chest. Any ideas about safe exercises in a laying or seated position is what I am here looking for. Right now I am just guessing and the doctors only answers are some out of date 20 year old print out of movements from a bad health textbook.

I am the first to agree that I should never have allowed myself to reach this point. I am not here for sympathy or to just whine about my life. I really do want to recover and honestly I don't want to die. I have the diet and nutrition down now, as I am limited on sodium content and some acid reflux. I am looking for either someone that has been morbidly obese and begun to recover and what kind of exercises they did to start out? or any professionals that are members that have some ideas or links to websites or videos I could do.

On a side note: 3 weeks ago I was up and moving around just fine. I was using a Recumbent bicycle for 20 mins 3 times a week. (not enough or maybe too much for my current condition). I was also doing basic moves from DDP Yoga to try and stretch my muscles. I do not understand how I could go from feeling out of shape and working out to not being able to barely stand up in only 23 days, without a major cardiac incident that I am being told I did not have yet.

Thank you for any helpful information offered and again I will not do anything without checking with a doctor, even if the doctor is tired of returning my messages on questions about my health.