I tend to dwell on problems that shouldn't matter anymore, and they make me depressed, how can i stop this?

People push our emotional ons. And the closer we are to them, the more they push. (This is my belief anyway). They do this unconsciously, so that we can become aware of them. So that we can clear them out. Heal them. That's why they say "For something to exist outside of ourselves, it must first exist inside of us" This is why I think you talk of fear of abandonment. The point of power is always in the present, so don't concentrate on future fears. Take this situation one step at a time, so you're not overwhelmed. Stay in the moment. Raising your self esteem is always good for this. Happy healing. All this stuff is happening to you right now because it's your "now issue". Don't worry, after you heal this, there'll be some next step appear. Hence the self esteem.