Moringa is cheap (usually free) and plentiful in the the Philippines - eat it daily. Young leaves raw in a hot soupy broth. Fish like sardines and small mackerel - also dirt cheap all over Asia. And eggs. Eat often - small amounts are OK. Most importantly - even in the smallest ways - try to build some muscle mass within your limits. Swing your legs over the bed. Light hand weights. Whatever you can do - start very small.

Hopeful and sending prayers.