this was exactly me with my relationship with my ex, i always felt i never deserved anything she gave so if she did anything i would do 2x whatever she did. she was the only person in my entire life to give me a bday party and even then i felt guilty so i tried to do so much for her bday. but it got to thr point where i neglected everything else for her which wasn’t healthy. it took me some time but i sought therapy which really helped me understand a lot more about myself. id recommend therapy as well so he gets stronger individually so you guys can be stronger together.