Sad that I can’t EBF my baby

I’m tired.. I have 9 weeks old LO and Ive been struggling with breast feeding since apparently he has suckling issue and that has affected his milk intake leading us to combo feed. I know fed is best but every time we need to give him formula I feel sad that I’m not enough. My husband has more than enough times said that my worth isn’t tied to me breastfeeding, but I feel sad that I can’t nurse him all by myself. Also, sometimes nursing and formula feeding takes so much time, he starts crying because he gets sleepy, so I feel he sleeps off without being completely satisfied. Though he has good pee count and poops every day, I feel sad that he cries at every feed. I wish my milk was enough and he could just feed himself to sleep. What’s worse, is that my elder sister did not have such problem, so I feel sad comparing myself to her (which I know I shouldn’t) thinking why did I get such a deal. I know it’s temporary phase and that in long term this doesn’t matter, but I can’t help feel all these things. Sometimes, I feel so numb that I don’t even bother looking at my child when he is my mother’s care. I’m afraid I’ll breakdown and not be able to stop.