weak body

Recently like my body not working very well leh. My right shoulder that part of the muscle cramped 2 times for like 10min.(last sat n today). Dunno wats going on.Kinda weird feeling,my hand still can move, no problem, but then feel like the pain from inside,around the ga lat dai area,hopefully dun come again,maybe just wrong posture studying too long,but I'm just stuying in normal position, sitting on a chair wif standard table height, wats going wrong?

btw my leg oso, kinda flat foot,recently dunno walk too much or wat,recently keeps like pain.So i temporarily wear my running shoe out to lectures ,reduced a bit with the shock absorbing,but when i wear my slippers then it get very bad,somemore always have to climb up n down to pantry.ai, ailments go away..i still got many things need to do..n i couldnt afford for any major treatment..

I shall eat more healthy, although now is already quite healthy ( whole grains, no maggie n more vege n fruits).More regular sleep, less coffee n tea....