How can i be more disciplined with my eating (ie. less junk food and soda and more of the healthy stuff)?

Small changes: Make small changes and set short, manageable goals. For example, give up one junk food for 2 wks. Find some healthy substitutes. After 2 wks, you may have the less-healthy food again, but only for a special occasion. Give up another one, and keep doing this as you get used to less junk food in your diet. Also add a bit more exercise every 2 wks.