These were your friends since you were kids. The dynamic where you’d vent all your problems and the immature teasing comes from having been so young when you met. You all didn’t know better due to your age.

But you’d hope that you’d all mature and the relationships would grow up, too. The teasing is mean and must not be tolerated. The venting you did for moral support which was then used against you is a common dynamic in friendships gone bad. I’ve experienced this myself and learned the hard way. So, I try to not vent too much and keep a boundary with friends. In more mature friendships there’s a degree of venting and support for issues, but with a limit. IMHO, having good times together enjoying experiences is the stuff of bonding friendships with a peppering of emotional support.

I don’t think you are at all in the wrong here. Maybe there is still a maturity the friendships with these two can elevate to and improve.

I had two similar friends as you describe since childhood. With one, we are still great friends. It’s just a healthy, supportive friendship. With the one who kept giving us both jabs veiled as humor, we both have had to cut ties with her. She could/would never grow up and improve. Honestly, over time she got much worse. Probably a disorder was behind her toxic behavior. But we certainly tried and gave her countless chances before cutting ties.