new to cleansing & fasting, need help

I am 29. I have a lot of digestion problems! My joints hurt all the time, and I get very constipated. I stopped eating glutin for almost 2 months and that helped tremondusly.I did a Liver-Flush 3 weeks ago and felt great. So I fell off the wagon and have been eating like crap the last 2 weeks I have been eating anything and not paying attention to what it is(a lot of glutin and sugar) Well the joint pain, digestion problems and constipation are back. So I have decided to fast. I tried the Master-Cleanse a while ago and did notmake it past day three. So I think I need one with more substance. I tried a juice fast today.I did end up having a banana and a small salad, I was so hungry. I am drinking a lot of water to help flush all the garbage out of my system. I have a few questions though. How much juice is too much? I did carrot, cukcumber, celery, green peppers, and tomato. then a fruit one of pineapple, grapefruit, orange and cantalope. I had to add water to the fruit. Are these mixtures ok? Also if I eat some walnuts or almonds (to help fill me) would this totally screw eveything up? How about if I had a small salad? I have horrible munchies!! Any helped would be apprieciated. Tweet