I got this, it’s like, sometimes you feel stupid about that, since you can’t feel happy. But it’s a process, and it’s normal to have ups and downs, you feel sad bc you did tried your best in the relationship. We feel sad and frustrated when we failed in Sth we have put lots of effort on. Have you considered therapy or building a supporting network? It helps you to learn how to cope with those nasty feelings. Also, acceptance and patience are important to me, like for me, I find accepting what has happened and wait it past patiently help. Meanwhile, I talk to ppl and do things that I like. Be kind to yourself x