I was in a relationship for a very long time with someone that required tiptoeing all over. You think you are doing it because you care about the person but ultimately you aren't forcing them to improve themselves and you are only building resentment, until you can't hold it back any more,

People with mental health issues deserve love and it's ok to have a relationship with them. You can be sensitive and supportive of them. But just as you need to be supportive of them, they have a duty if they are choosing to be in a relationship to work on managing their issues. If they aren't willing or are unable to then the relationship can quickly become toxic and abusive.