How to Stay Together and Secluded!

I am not sure how to word this but it's lengthy and I need some advice. A bit of the background story. I am 20 and have been with my now ex for 4 years on and off. We recently split for what I think is for good. His family has never thought I was good enough because he and I fought all the time, have different opinions, and they are very verbal and judgy. So we broke up for a few months, and then got back togther for only a month before his family interfered. His family told him it's them or me. So I suggested a compromise to keep us somehow and not have them find out and he said how and I have no idea how. Please help me!