Issues with handling emotions. Please.

I feel like an incapable person because I am unable to support my partner's major career changes due to lack of trust in his decision. It is seriously damaging our relationship and is building walls between our communication. He feels unsupported and unloved by me and I have been abusive towards him which I am deeply guilty and ashamed of. He supports and forgives me always but I am not able to do the same or accept him or his decision because of my own doubts. How can I help him and help myself. Often at times it is difficult for me to handle other people with trauma because I never could resolve mine. I feel incapable when I am unable to help him out although there is nothing I can really do but support him. But I have my doubts which are limiting me from doing so. Help me please.