My boyfriend won't work out

I want to start off by saying that I love him no matter what. I'm asking for support/advice, not judgment or rudeness.

So my boyfriend used to be a pretty fit guy but he's steadily gained weight these last 3.5 years. Now, I DO NOT care. I love him and am attracted to him regardless. Also, he really doesn't look as big as he insists that he looks. But he just doesn't feel the same way about himself.

I spent months upon months just being loving and telling him that he looks good no matter what, that he's still sexy, that he shouldn't be so hard on himself, etc.

Well, he himself told me that he needs tough love to be motivated and that other methods don't help him. So, I agreed to be tougher with him (even though I really didn't want to because I just want to be loving) but it's what he wanted and if it helps motivate him and feel better about himself, then I'll do it. I never ever have told him he's fat or anything. My way of being "tough" with him was saying to stop making excuses about why he's not working and just go out and do it. When he's come up with an excuse, I'd say he should stop being lazy and that he's never going to see any change if he doesn't put in the work. Apparently this bothered him because he doesn't appreciate being called lazy after working 10+ hours every day. I felt terrible for making him feel bad especially because I'm not the tough love type and all of this backfired.

So, now I try to motivate him by getting him to join me on my workouts and eating healthy. He still isn't really responding to this though.

Idk what to do now. I just want him to feel good about himself. I don't care if he works out or not but no matter how often I insist that he's sexy af, he hates how "fat" he's gotten and beats himself up about it.

So how can I motivate him? Is there anything I can do? I hate seeing him so negative about himself 😕