Kicking Him Out?

I'm a melancholic who has struggled with depression and suicidal thoughts since the age of about eleven. I've never been diagnosed with anything (mostly because my experiences with therapists have been very negative), but I'm starting to wonder if I'm mildly bipolar.

Anyway, relatively unrelated to the information above, is my problem. I've been with my boyfriend for about three years, and not once has he held a job for more than a month. I keep waiting for him to pick up the slack, but....well, obviously he hasn't, since I'm whining about it here.

He has pretty much absorbed my entire personality, my dreams and aspirations, and now is entertaining the fantasy of being a children's book author, so that he can stay at home all day and 'get paid'. Regardless, I want him out. It's gotten to the point that I can't even delude myself into loving him anymore. What I'm worried about is being alone. What should I do? I'm afraid that being by myself with no support system will trigger (well, worsen) my suicidal thoughts. I feel like I've become codependent to the point that it won't be okay.

Any suggestions?