What can be done if my boyfriend is getting deported?

I'm 18 years old. He came in the US when he was 8 years old, with his grandparents and sisters. He has residence permit, indefinite leave to remain in the US. On his passport, the type of permit is settlement. But while he was living in the US he got put in foster care and been in out of homes. He then finally settled with a family. When he turned 18 and the foster family wasn't getting any more money from him, they then kicked him out and he was living in a hostel. While he was living in a hostel, he got in the wrong crowd of people and got himself in to trouble. We meet not long after. We were going out for 1 year in that time we had a three week gap. In that three week gap, he got another girl pregnant. After the three week gap, we got back together and not long after he was sentenced for 2 and half years does 15 months in prison. We been together now over 2 years. We were planning on getting married before he went to jail but never got chance to. He has a daughter who is 1. His mother die while he was in prison so he has nothing over in his country. Do we have a good case or not. If not am I able to go with him on the same plane and I haven't ever been on one before so very scared and plus I don't have a clue where I’m going.