Weight management with Prednisone, Biologics and DMARDS

Hello!
I am a 39yo female with 2 children. My children are old enough to care for themselves at ages 11 and 16 so in that respect I am lucky. I have had a 2 plus year long MAJOR flare brought upon by an accident and 2 subsequent major surgeries. My Rheumy has prescribed good ol' Prednisone. I am a medication wimp so we started at 5mg which made me feel like i was on crack with hot flashes and am now up to 15mg. I take 8 methotrexate once per week. I have instructions to NOT push it and NOT workout because I am in constant pain and have swelling, redness and heat to my left hip and other joints. The medications have freed up some of my motion and I find that I am a bit less stiff however the pain is still unbearable at times. It is frustrating because I want to run, ride my horses and hike to work off this extra weight that I have put on as a result of stress, depression, medications and being mostly sedentary. I do little strengthening exercises and strethcing but when you are pushing 40 and above it isn't enough to get that metabolism burning like it did when I was in my teens, 20's and even 30's. I really noticed it slow in the past 2 years or so.
I am "blogging" about this now because I would love to hear from anyone who shares similar experiences with medication and needing to take it easy. How has it been for weight management with you? I have to add, when this first flared up I lost WAY too much weight too quickly as a result of the disease process and later once the stress response went on and on it went the opposite direction. I still have a bit to go but do consider myself to be a healthy weight right now at 155 on a 5'5" frame but my normal weight is around 140. That is where I feel less stress on my joints so I have been using a healthy balanced diet to help it go down.
My Rheumy says to NOT attempt any major weight loss diet and just eat as healthy as I can. She seems to think that attempting weight loss would only put more stress on my already immunosuppressed and stressed body. SO....stretching, mild yoga and other strengthening exercises are all I have managed thus far and to be honest, some days it is near impossible to leave the couch or bed. I would love to hear from anyone out there who has any input!!!
I am a seropositive psoriatic arthritis and EDS/hypermobility syndrome patient. My Rheumy also strongly believes I have Ankylosing Spondylitis however the initial labs tested negative. That said, as most already know who suffer from autoimmune diseases the bloodwork means squat in many cases and you can be seronegative yet still suffer from said disease process......sigh. :-)
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