Always cold, tired and bruise easily. Is it dehydration, vitamins or more?

I am 26 years old and have constantly had a problem with being cold, particularly in my extremities. I am also tired all the time, no matter how much sleep I get. Also, I've always bruised easily, but recently, I've noticed that even just leaning my face on my hand for a bit, I get a bruise (not huge, but definitely a lot visible broken blood vessels so that I have to cover it with makeup). This just seems very odd to me. I know that I dont drink enough water, and my husband thinks it's all because of that, but i'm not sure. I also take a Women's One a Day and eat ok, so not sure why vitamins would be messed up. I had one instance in my life where I tested hypothyroid, but never again since, and not sure if it's relevant, but when I give blood, it takes like 45 minutes, really slow. I've also had problems with faintness, but not really all the time, but every so often. I was wondering if I should go see a doctor, or if this was all just normal.