Why I'm tired all the time?

This has only been going on a month, tops.

I have been working third shift for two years. I also have a second job that I work a couple of days a week, usually really late second shift. Because I've been so tired, I've made sure I sleep the same time every night (or day). Sometimes I would sleep whenever on my days off or on my days I work my second job. However, since my tiredness has affected me, I've been trying to sleep better hours.

I'm not a coffee drinker, but I'll drink a 20 oz. pop (maybe) during my shift.

I try to drink enough water, but my eating habits aren't great. I tend to only eat on my lunch breaks at work, and maybe snack when I'm home. I know that can be a cause my symptoms, and I've already decided to eat better when I do eat, but I'm still wondering about my fatigue.

I move around a LOT on my job. It gives me a lot of exercise. I know exercise is recommend, but I am very active.

My room is dark and comfortable. I have a fan for background noise and I usually fall asleep by the TV (I have been doing that for years.)

I have always had trouble falling asleep, but I've never had insomnia or too much lack of sleep.

There's been several times where I've stayed up for 24 hours because of work and then slept, but I don't think anything like that has happened to me recently. Same with having nights of only four hours of sleep or so.

I've been trying to sleep better lately, specifically because of my tiredness.

Sorry for being so descriptive. I just wanted to cover all the bases.

Thanks. :)

Almost forgot, I'm a 25 year old woman. :)