He told me about his mental health

He needs both medication & therapy…
This would be a Nope for me.

Get more information. How severe and how long has he suffered this condition? How does it manifest? Does he have any idea what the root cause is?

It’s actually good he’s off the meds and seeing a counselor because the meds only control the symptoms, they don’t solve the underlying issue – counseling does that. You are wise to be wary. If this isn’t a thing he’s had for years, he may be able to solve it. Ask if he has a plan for handling issues in a relationship that could trigger his anxiety.

If he’s had this for years, you are well in your rights to walk away. And don’t feel guilty. There are so many posts here about people dealing with anxiety and it’s badly affecting their relationship. It really needs to be addressed and under control before someone can be in a relationship, otherwise it’s unfair on the other person.

You don’t need to automatically write him off over this since he’s actively getting help and has been for some time, unless you’re already sure it doesn’t mesh with what you’re looking for and won’t be healthy for you (if you’re already thinking through your decisions based on your fears, that’s not good). However, in addition to asking more questions, you need to make sure he’s never taking his issues out on you. The red flag is him saying he may get aggressive towards you. Because if that’s the case, then he doesn’t actually have his condition managed. A good partner can have a bad day but should not take it out on you. You shouldn’t put up with bad behavior just because he’s got issues. Issues explains why but is not an excuse. So have another conversation for more information and if you decide to continue getting to know him, observe your dynamic without making excuses from there, and see how it goes. If he doesn’t show up for you as a consistently good partner, then it will be time to leave. If you continue with him now, go slow on emotional investment until you have some more information and have gotten to know him and his condition better. Don’t rush forward and excuse it with, but I’ve caught feelings!, because that’s what leads to the roller coasters.

That sounds like a plan. The way to set boundaries is to keep your words and actions the same. If you say you won’t tolerate aggressiveness and then it happens, you need to then keep your word in actions, even if that means leaving or ending things. An apology from him and then repeat behavior just leads to a toxic relationship.

I also wouldn’t assume he’s telling you this to be vulnerable… he may also be doing it to feel like he’s “warned” you. If it turns out he has full-on anger management problems rather than is just a bit moody or anxious sometimes, do not stick around.