Please help me realize that wanting to lose weight isn’t selfish.

I (23f) am married (22m) and have one child (2f). My pregnancy was horrible; I had severe preeclampsia and gained weight like crazy. Before my pregnancy I weighed 130lbs and after it I weighed 180lbs. I am only 5feet tall so I felt awful with all the weight gain. I felt like I looked huge and I felt huge. I am now around 165-170lbs and I still don’t feel great about myself. My husband is taking us on a trip this weekend to the hotel he works at for Valentine’s Day and I’m absolutely dreading it because I want to go to the pool there but I feel so embarrassed for him. I feel like everyone will be looking at me and I know that’s just because I don’t like what I see in the mirror. BUT I am writing here because I have talked to my husband about working out and going on a diet. He is very very pushy about not wanting me to do this. He has had a history of p0rn addiction and I know the other women he has looked at/been interested in weigh substantially less than me. I know I am not a large person in any way so I fell silly wanting to lose weight but I just hate how I look. I hate looking at myself in the mirror but every time I bring it up with him he just shuts down and almost gets mad at me for even wanting to lose any weight. I want to get a walking pad and a stepper for our apartment so I can work out/move around more while I’m alone with our child as I am a sahm. He insinuates that I’m being selfish for wanting to get these items (secondhand) because my attention will be on myself instead of our child. I just need someone to tell me I’m not being selfish for wanting to lose weight and better myself. I want to love the way I look. I want to keep up with my child more. I want to walk up our 4story apartment and not be winded. I don’t want to feel guilty for prioritizing myself for once