Aw dear!
Do you keep a diary of your food etc? I've found doing that religiously on here has really helped!
Do you know what your triggers are? I.e. why do you get to lunchtime then go off piste?
I have an RC book somewhere, and love one of her recipes (black-eyed bean casserole) so I am guessing you are quite happy with the diet itself?
Can you get your hubby/daughter to go out riding or something with you? I try and do that with my wee lad.
You have 3 weeks till the beginning of August, it's not so long really. What I mean is - if you take one day at a time, write it all down - look for the danger points - you could do a lot of good in that time. And the three weeks will fly by, then next thing you know, you could have knocked off quite a few lbs!