About relationship. Should i do doctor?

I have a girlfriend named isha. We both love each other. We care for each other and love a lot. We also made sexual intercourse. We are also in same profession. My parents are worried about my career so they asked me get away from her. We both are doing mbbs but in nearby colleges. Isha has a boyfriend manik 3 years ago now he is in Russia now doing mbbs. They were in a happy relationship that time but not made any sexual intercourse. But now due to distance she is more close to me. She is worried about when he arrive India after completing mbbs who will she chose. She love manik as well as me. But now she can't be with manik. She is with me for now. I feel jealous of manik when she talk to him,  Post on Facebook about him.Well she also post with me .  I think of leaving her but i love her a lot and after a discussion i again start being with her. What should i do doctor?