You know what the problem is? Two of the three jobs you have had are easy high school grad (at best) and you were only able to hold them down 4 months and 6 months? Then you have what sounds like one degreed job (your most recent) and you were out after 4 months? And you have been unemployed for 3 years since then?
This is red flag city. If I was a hiring manager, this screams to me that for SOME reason, you can't hold down jobs and are now sitting on a lengthy period of unemployment. Hiring managers are likely thinking, what's the issue? Drug problems? Pscyho personality? Too irresponsible to come to work/not able to do the job/constantly gets fired?
Don't get me wrong - apart from that, you resume says you are smart. Unfortunately, a lot of smart people have some kind of deficiency (drugs, irresponsible, can't get projects done per company rules, etc.) that mean they can't hold down a job.
WHATEVER the issue is (and there IS an issue) with this kind of spotty work history, you need to be honest with yourself and get it taken care of.