Solveing health problems?

I know I need to try and error with health things to help me but it costs money which I don't have lots of. So I wondered if anyone had any helpful advice. I get eczema, I seem to have IBS when i try having milk and dairy things I don't get on with, I have intolerance's to different foods, mood swings, tiredness, my joints mostly my knees seems to hurt alot but not sure why, I get very weak sometimes. Iv tried the doctors but they dont help me, I crave for sugery food, I get depressed alot (Im trying to do lots of exerise though) I try to eat as healthy as possible but it still doesnt help me. Colon cleansing, acupuncture and all the other health things I don't know whats going to help me. Can someone help me?