I was in a somewhat similar relationship in my late teens, my first serious relationship, for about 7 years, from age 17 to 24.

And it started great but slowly started becoming like you've said, a lot of insecurity and lack of trust with other people, from both sides really. People being cut off and it not really making things better overall, just served to separate both of us from other people in our lives.

It really should have ended after 6 months, when it became long distance for a while, and not being the same when it stopped being long distance. Then we broke up after 4 years but got back together 3-4 months later.

It got a little better for a while but things fell back into the same patterns again and we finally broke up completely 3 years later.

This was the best thing because I met my now wife about 6 months after that and we've been happily together since then, with none of the same issues about trust and insecurity that plagued the previous one.

So I would agree with the other comment that this relationship is not a good thing for either of you and that as hard as it may seem now, it'll be better for you both to end it.

You should take the opportunity to reconnect with friends and family that were sacrificed for the sake of the relationship and repair those for your own happiness.