Just wanted to add that it is a good idea to keep a written record of any contact, phone calls etc you have with him, and maybe journal about past events or find journal entries where you describe any abuse or substance use. May come in handy later.
I know when I was in BC, you could, for free, meet with your ex and a mediator type person, and hammer out an agreement and they would file it for you in the courts. Trying to remember the name of the office - there's one at the corner of 1st and Commercial (upstairs) in Vancouver. That's only if you feel coming to an agreement with him would be possible, and you would be okay being in the same room with him.
Also if you are in Vancouver, call the YWCA (www.ywcavan.org
) about their single moms groups (they also have some housing for single moms).
In terms of support vs being left alone, I guess it's what matters to you, what you need, what he can provide and how much you mind your child being with him (alone). I opted for being left alone, because I knew my ex wouldn't be able to provide much anyway. Going through court can give abusive ex's a way of getting to you or making your life difficult, and some people feel victimized by the legal system. (family law in BC www.familylaw.lss.bc.ca
Money-wise, I'd look into daycare subsidy (getting childcare is such a headache in BC but at least subsidy will partially cover nannies and home daycare), OSAP student loans etc. Apply to housing co-ops (chf.bc.ca) and maybe also call BC Housing. Make sure you are getting your Canadian child tax benefit, and universal child tax benefit. There is also a rental assistance program for low-income people that is worth between $50 - $750 a month http://www.bchousing.org/programs/RAP
). The neighbourhood houses are often a good source of info, free services (like classes and consultations) and community (ie drop-ins and community dinners). Family places also have some services.
The Vancouver Status of Women has two publications that they update every few years - the single mother's resource guide and also the welfare resource guide for women... you need to call them to order (http://www.vsw.ca/publications.htm
I'm also totally biased but I think that being self-employed (work at home) is a good thing when you are a single mom, because it gives you flexibility. You do have to choose carefully and structure your business properly, so it doesn't take all your time. Find something you can charge enough hourly, so at least $60-70 an hour, and find a network or some outlet that helps you get out of the house on a regular basis. You do go a bit out of the system, so you need to look at whether you want to pay into EI etc.
Good luck and if you need some connections with single moms in either Nelson, or Vancouver, I could maybe help you.