Keeping the faith is the only thing that can help. Granted my weight gain at the minute is because I am suck in a foreign country, with no real friends here and my OH works all week quite hard.. But I will get over it and I will be okay!
Emma, thats quite a let down from your consultant. I left group because, although mine was wonderful, she was too nice.. I suppose the main things you could do are stock up on pots of low cal jelly, get some alpen light bars and mugshots in! Try and keep whatever area you have a low syn zone so even if you nibble on stuff, that it be light in calories and hopefully not too gainful!
Can you have a kettle? When I was really broke (at one point!), to make pasta and rice, I would boil the kettle, throw it on top of the pasta, cover the pasta with a lid and put a tea towel over it and in 15 minutes the pasta was soft. I know it sounds daft but even that helped me?