My father is having an extramarital affair. Part of me wants to end my relationship with him for cheating on my mom, but i worry that he will be depressed as he loves me a lot. How do I deal with this situation?

I understand that this situation must be difficult for you to be in. Personally I know what it is like to be forced to pick sides between parents, and it is not easy to be in that position. You may also find it beneficial to talk to a therapist if you need advice. I believe that if you tried to communicate your feelings about this situation with your father, it may provide you with the opportunity to find clarity in your decision. It may also help you to take some time to process the situation to determine what emotions you are feeling towards the situation.