Don't know what the problem really is ??

Been in a relationship now for 8 yrs and 5 mths all has been good until about 6 mth ago even after having my daughter last February, I love my partner 2 bit more than any man in my life and up until about 6 mth ago I felt he felt the same until 1 nite he knocked my self confidence and told me I was a bit big now sex is more or less none exsistant but when I put the past behind and make a huge effort he knocks me back ! and it takes more than alot 2 rebuild my self confidence up 2 offer him the opportunity back into my own little bubble ,Weight has always been a problem in my life since I was 16 but because I love him I felt relaxed around him and didn't think I had out to worry about I didn't until 1 day my weight was brought up yet again !!! And has haunted me ever since HELP!!! , It's not only crushing me but the children are now starting to pick up on it and I don't only want them 2 feel the same as me but I don't want to lose him either