that sounds tough OP, the kids are a bit thoughtless (normal for teens) but DH sounds selfish and a bit uncaring, this needs addressing.
What does he say if you tell him you feel excluded and sad about it?
I have two teen boys, and lots of hobbies going on in this house.
My boys do not exactly actively want to spend time with me
. not in a nasty way, it's just that oldest is 17 and has his own life, a serious girlfriend he spends lots of time with, and lots of hobbies (music, gigs).
The younger one (15) just want to do his very extensive martial arts stuff (some of it with DH), hang out with his mates or chill on the X-Box/Netflix alone.
So maybe it is just how it is at this age.
What I try to do, and what might work for you, is try and share some of their interests. For example, I watched a Starwars movie with them yesterday at home (Rogue One), we discussed it over dinner, it is a way to include myself in their world, we all liked it. We also watch tv series like "The Office" or "friends" every now and then. We also have dinner together most nights, but sometimes that is all I see of them for the day.
I have started to become very hobby focused myself, and accept the boys need me less, and just go out and do my own thing a lot.
It's not always easy, you have my sympathy! And your husband shoudl really be more supportive and caring!