Just to play devil's advocate (and bear in mind I don't know you, what you look like, I'm only going on the information available to me, and I don't care regardless, just trying to offer you a different viewpoint from what you've already been told)

I'm still 20 over what I consider to be my ideal

and

but there's def plenty of cellulite

Unless your 'ideal' is obese there's no possible way you have a lot of cellulite and are only 20lbs overweight. So either you're being too generous with the 20lb estimate or too critical of yourself and the cellulite but definitely one of the two.

Twice now I've been really interested in a girl romantically and just not being interested physically due to their weight. I can't tell you how frustrating it is. I tried to get them interested in going for jogs with me and my dog, out for bike rides, hikes, etc, and unfortunately I ended up having to break things off because I just wasn't sexually attracted to them.

I'd say he's already at the end of his ropes there but you do mention you go to the gym with him from what I can only assume is regularly (a guy really into health like him is probably going ~<5 times a week) so even if you're only going 2-3 days a week you're putting in effort and he should respect that. However, he may feel you're not putting in enough effort and he's saying these things in a last ditch effort to try to get you aboard the same level of health as he is.

Just my $0.02 on the situation. Also, I don't know your diet but what worked like a miracle for me when I was trying to lose weight was not drinking any calories. I've always been really active, ate healthy (no fast food/frozen dinners/etc), didn't eat sweets, and didn't drink soda but I was still 40lbs overweight. I was just drinking way too many calories with beer (I did the math and some nights I would be drinking nearly 2-3k/calories in just beer). I went from drinking beer daily to liquor on the weekends and the lbs melted off with literally no effort on my part. So, if no liquid calories is something you haven't tried, it may be worth trying out for a month or two.