Don't get discouraged! I actually had very similar job history a couple years ago, including periods of unemployment. I've been working steadily for the last couple years and have only seen my career go up :) my dad used to tell me, "you only need one interview to go right" and I would get SO annoyed because I was going on so many interviews. But that one went right and I landed an awesome job with a fantastic company!

It seems like the pits now, I understand I really do. If it makes you feel better: I once worked picking up dog shit for a dog park because I got fired from my door-to-door solicitation job. You can always climb up! Apply for anything and everything and go to every single interview, even if you don't want the job or aren't qualified the interviews are good practice! Every job has an advancement opportunity for the right candidate, so don't apply just thinking you'll be stuck at the bottom.

Go into every interview fresh-faced, and tailor your cover letter for each and every job. You just have to connect to the right person.