wow, you really have had a tough time over the last few years. Teenagers can be a bit blind to what life is like for their parents, I see it in my teenage DD - and I also remember what I was like at her age! They just see things differently, and yes they can be very selfish. Might be time for a bit of tough love?

Chances are once they grow up a bit, they will see what you have done for them & have some gratitude...you may well find it all turns around for the better in a few years

ETA - second what Muppity said on the counselling , good idea