I'm not sure if I can help any, mostly because I've had a problem with picturing the future as well. I think that actually coming to the point when you think suicide is an answer, you already gave up any plans for the future. I sometimes find myself actually surprised to still be around.
The only thing I can suggest is 'baby steps'. Start with some small goals. I picked some easy ones. I took some community classes, ones that are offered free or for only a few bucks. This can be school structured ones or simply an art or craft one. Something that sounds interesting. Then make some bigger goals, things you want to do in a year or so. Like plan a vacation. You can always adjust the times and everything as needed. It could be a short weekend trip or a few weeks somewhere that sounds nice. Invite others, it will be funner that way. Volunteering places is also a good thing to do. I plan on finding out where I can help out once the weather is nicer.
If you can make goals and plan ahead for 'little things' that you like, it makes it seem more possible to imagine other 'big things' like a carrier and family. Also, by finding out the type of things you enjoy doing, it's easier to picture the type of job you want.
I hope that helps some.