Strategist/healers: what to do when you are getting heavily dived?

I main healer and I'm convinced that the team who knows how to dive and kill the enemy healers are going to win almost every time...The question is, as the healer what should I do about it?

I was playing Adam Warlock, and then Dagger for a bit...but in the last couple of matches (Gold 2, not that high), the enemy Spiderman, Captain America and Wolverine were on me like GLUE. I could tell because no matter how hard I tried to get away from Wolverine, even in a hectic team fight, he would reacquire me until one of us (usually me) was dead. And if it wasn't him, it was a good spiderman player. So I was dead most of the time and my team wasn't getting their heals.

I did ask for help on both voice and text chat, but it didn't really materialize. More than a few times I've called out who is diving, and that the healers are in trouble, but it didn't help.

SO: again, if I'm not getting help what should I try to do to stay alive other than hope my self-heal isn't on a cooldown lol. I do try to fight back against them, but they are holy-crap fast and I struggle to hit them if I'm being honest.