Weight loss with bf?

Idk I feel like I need to lose a few pounds I love my body but recently I feel like it would help my self esteem to be maybe 50lbs lighter. I’m 5’6ft and 240lbs and I was talking with my boyfriend and he’s totally fine with whatever size I am but I offhandedly said I wanna lose weight and he was so supportive and said we could lose it together. Then I kinda backed out of the decision because I was worried he wouldn’t find me attractive when we would work out and I’m really shy and like working out in private and he’s a gym guy all the way. He is totally up to helping me but I just don’t know if I have the ability to do this right now. So I told him maybe not rn but later. Am I being silly?