2 stone to lose, but not sure how.

[CaulkheadNorth]

I've had eating disorders from 12 upwards. The last two years I've become a lot happier and eat a lot better.

I've gained weight recently due to changing jobs and not purging and I now need to drop some weight for my clothes to fit better.

I find anything with numbers - calorie counting, MFP etc spirals me into unhealthy territory, along with dropping food groups, like low carb or low sugar.

Is the best plan to up my exercise and eat the same, or change eating patterns (3 meals, more veg etc?)

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!!

I think I also still have a mindset of "I can eat this, I haven't eaten all day" when I'm reality I will have done now.

Portion size makes sense. I can do that without it feeling like a "thing".

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!