No worries about that, I have learned what I can do and what not 
Actually slow practice is not really efficient for me. The way it works is that with vigorous (even hard) exercise the muscles do loosen up and after maybe an hour or so my muscles start feeling like they should, soft and flexible. The more I work the better they are. But exercise does not benefit me like it should, because the muscles tense/cramp again during rest so the effect of physical exercise is never permanent. I sometimes have trouble getting up from the bed in the morning and walking, but in a couple of hours I may function normally for the whole day. The other symptom I have is muscle weakness which also causes problems with posture and all that is not very good for playing I guess...
How many pinkies do you have?? 
Ouch, this is exactly why you need to stretch your warm up out, from least to greatest. When your muscles are cramped, massage them and ONLY I REPEAT ONLY do slow movements!
What I meant is, you need to think of your warm up routine. If you dont have one, thats fine. But the thing about tension is that it is a protective mechanism for our bodies. When you sit down at the piano first, you are tense. There are only physical ways to relieve physical tension. Even if you think you can meditate into free movement, your mind will still have to do a lot of work. Without a warm up...and this is the thing about warm ups:they can be wrong. You have to know what warming up is. Think:what is the goal for today's practice? Is it playing through a presto section? Then your warm up should be slow and deliberate. Probably work on slower and shorter pieces for a while before you will actually be warm. Never start with a fast piece. The tension will kick in much sooner than if you work your way through it, and you will have a bigger cramp. Its like a massage. You need at least an hour sometimes. If your goals are different, you still should plan everything out.
If you are having such a difficult time getting up, i do too. I have depression and adhd(or you could call it bipolar...haha)
It affects my physical state a great deal. When I dont feel good, I take a really long time to start the day(im not allowed caffeine). But, when it finally kicks in, it is wonderful, and totally worth the wait, meaning you wait for your body to be ready, you prepare your mind and plan/think/talk to yourself while your body is relaxed.
It all should take a very long time and every little thing is a huge deal! Naturally! LOL
Hey Outin, what is your schedule like? Do you work and then practice in the evening? On the weekends, are you free to practice?
And i only have 2 pinkies

hahaa