How do I know if breaking up is the right thing to do?

It’s important to know that there's a lot you can do to help a relationship. Have you done your due diligence? Have you tried couples therapy? If you really feel like you want this to work and you love this person but you're just not getting along, you should probably reach out for help and acknowledge that you don’t have the skills to fix the relationship, which is totally fine. There's nothing wrong with that. No one taught you in school how to have a healthy relationship. You should also consider your feelings toward this person. Was there ever a strong connection or a strong love there, or did you just rationalize yourself into this relationship by thinking he’ll be a good partner because of this quality or that quality. If there was never a strong connection there, it might be in your best interest to let it go.