I used to be bulimic and like you the minute I start counting stuff it spirals out of control. I found the best thing for me was to reduce portion sizes (and up the size of the veg part) E.g. 2 slices of pizza and lots of salad Small palm size piece of lasagne and some veg Couple of crisps out of the kids packet rather than a whole one myself. 1 Jaffa cake instead of 10!!
Yes you can lose weight just with exercise! It is slow though ( in comparison to just diet or diet + exercise). The idea is that you have to create a calorie deficit but don't eat any more that you would normally do even if very hungry!