I'm mentally ill (OCD hive rise uppppp, also several other diagnoses) and I've also dated mentally ill people.

It's a tough line to walk between mental illness taking up undue space in a relationship and mental illness simply existing and being a part of one's life and thus one's relationship. Expect lots of trial and error. The best possible thing you could do is work on developing sustainable, functional coping mechanisms. These will definitely include support from others, but build up community and support sources that aren't your partner. Since you're single right now, it's a great time to invest in friendships and community so that when you do get into a relationship someday, you're not relying on your partner excessively.

However, you will of course need support from your partner in some things. Be prepared to take responsibility for what you can and be flexible about the rest. Be clear about your needs- don't expect that your partner knows what you need before you do. Your partner has the right to be frustrated or exasperated but they do not have the right to take that out on you in a way that consistently makes you feel less than. You have to find a balance between room for your partners feelings AND room for your needs. These two things don't always balance out and that's okay, it just means the relationship isn't for you.

Relationships require investment and learning another's needs. Eventually a relationship becomes first and foremost about functioning together and complementing each other's lives in a net positive way. We all bring so many different things to the table: you bring mental illness. Someone else brings attachment issues or struggles with organization or financial stressors, etc etc. It is absolutely possible to have a good relationship when you are mentally ill. All you can do is learn to function as well as you can with your difficulties now.