Massive Mood swings? Depression or hormones?

I am a 23 yr old female. I work out 4-5 days a week and have a very active daily life. I have hobbies like reading, painting, dancing, cooking, etc. I eat lots of vegetables and fruits and some lean meats. I take my vitamins everyday and drink 2-4Ls of water a day. I have sex 2-4 times a week and have an amazing partner and I love my job!

BUT I find I can be positive and outgoing one moment and than moody, depressed and have no motivation for anything or anyone. I just want to go to bed and its hard to even get up and do anything I will have 2-3 days of this than I will go back to normal. I was taking St. Johns Wort for nervousness and depression but it never fully worked.

I am moody, bitchy, my skin breaks out for NO reason. I could be in the middle of a nice dinner to being at my desk at work. I'd have to excuse myself to go to my care and sit and cry or sit and smell some lavender oil i bring with me.

It affects my relationship with my friends, boyfirend and family. I want to hide some days because I don't want to hurt anyone but when I hide i end up just being a ***** to myself but than i burn it off than i get back to normal. But when I am around people my mood swings like crazy. I have been like this for the past month and a bit. I thought I might of been pregnant but im not.

Is it depression or hormones? Besides going to see my doctor how can I self help myself? I've turned to essential oils and carry around a bag of dried lavender and oil to smell when I feel moody. I don't want to turn to prescription drugs. I write in a journal and that seems to help.

I just want to see if anyone else has similar problems or has advice? No stupid answers douche bags.

Thanks