Tashy a walk - a nice fast walk is very good exercise! You will lose weight walking and eating sensibly. I was in the same place as you a few months ago - I hit 83.5kg, my heaviest for about 10 years - mostly I hover around teh 75kg mark and I was talking myself into the same thinking - well I can't do anything about this, I feel so crap about myself, I'll just eat a pile of crap to make myself feel better.
Thing is, it's only temporary pleasure, because you get back on the scales or try to find something to wear and you feel just as bad if not worse.
Taking the first step is the hardest, but when I get back into line, I always feel better about myself, always - exercise does give me more energy and I feel so much better about myself.

You can do this!!!