Hi Prickly - I agree with the above - love yourself first. I have been in a similar situation. I have moved 5,000 miles to be with my boyfriend and I felt really self concious about my weight. I think perhaps putting off the visit/move might just add more stress because now you've put yourself on a countdown of sorts.
In my experience men can really hinder weight loss. I'm not saying get rid of your boyfriend, but while we already feel self concious being overweight, the thought of what a guy thinks just adds to it. The only way I have found to lose the weight reliably is to just concentrate on myself. One day at a time and not to worry about what a guy may think. If the guy does not like me right now (heavy) then he is superficial and not worth my time. Maybe this thought process gets easier with age. (I am 33). You also have to realise that the more stress you put on yourself the harder it is for your body to lose weight.
I have been in several emotionally abusive relationships, and have left my last one for good I hope. (Last one was not chosen, it was having to live with an NPD/PA family member) Every time stress has happened I put on weight. Every time I am out of a stressful period I drop the weight. Stress factors in a lot so try to focus on the weight loss and not so much about what this guy may think.
PM me any time if you'd like to talk.