I'm sorry that your friends called you out for that. They should want to support you, but I know that it's frustrating to hear other people's problems and to not be able to help, so I guess I get it too.
I was going to come here and suggest journaling but that's really the only other option specifically for venting that I know of. If you're consistent, it works. If you physically don't feel like writing in the moment, you can also type up an entry on your computer or phone, or take a recording of yourself talking as well. Those are valid forms of journaling your feelings so don't feel constricted to the pen and paper if you physically cannot bring yourself to write. I personally have a Whatsapp chat with myself and I send voicenotes there sometimes just to talk to myself, lol.
Hobbies can be good too! If you don't feel like venting in a journal, why not doodle your feelings out? Why not splatter a bunch of paint on something until you're not upset anymore (you can even look into those journals that prompt you to ruin the pages in different ways when you're feeling bad, I think one of them is called "Wreck This Journal")? Why not go to a gym and run on the treadmill until all those negative feelings disappear? Why not get into the kitchen and start baking so you could turn the bad feelings into something yummy to lift your spirits sometimes? There's a lot of things you could do!
I'm still sorry about the situation with your friends though. I hope they aren't just outright dismissing you when you need them.