Went vegan and feel WORSE than ever...

Just a little backstory on me. Hopefully someone can give me some advice or insight! I am currently 21 years old and have never been pregnant. I started using hormonal birth control when I was 15. When I was 15 or so, I tried being vegetarian but stopped when I felt extremely fatigued and dizzy all the time. I found out I had low iron levels so I would periodically take iron supplements, but I tend to get very nauseous and get diarrhea from any type of supplement so right now I don't take any. I stopped all forms of hormonal birth control 8 months ago and it turned out to be a fantastic decision. My periods of course got somewhat heavier but have evened out quite a bit now. For the first time EVER my skin cleared up! That was the best benefit of all. I had struggled with extremely painful and persistent acne for 6 years and for some reason it never occurred to me to stop taking birth control and that was what finally did it!

Fast forward to now. I have been almost 100% vegan for 2 weeks now. I did not "transition" at all. I decided to just jump right in, but now I think that may have been a mistake. I'm not experiencing the dizziness and fatigue like I did when I was younger, but I am getting all kinds of other terrible side effects. First of all, I've had chronic stomach problems (constipation, nausea, diarrhea, etc.) for years now. I thought cutting out dairy might finally solve it, but it has had the opposite effect. My stomach is worse than ever and is constantly bloated and gassy. It has improved slightly in the past few days but is still worse than before. Also, I immediately started breaking out again. My skin is quickly returning to how it used to be. I have constant headaches and muscle aches despite the fact that I am trying very hard to eat regularly and drink lots of water. My period is currently late, which NEVER used to happen. I'm on day 33 of my cycle and haven't even had any spotting. Overall, I just feel pretty awful.

I don't know what I'm doing wrong. I'm eating a wide variety of foods and trying to make sure I get enough protein and healthy fats. It's so frustrating because this is a choice I truly want to make and I feel like my body is failing me. Taking supplements can be a risk for me because like I said, it tends to make me feel sick and I don't want to feel even worse than I already do. My skin is not getting any better and it's constantly hurting from the inflammation which makes my headaches worse. I'm thinking about trying to see an allergist or dietician or something. My best guess is that it's a hormonal reaction from my changing diet and increase in soy consumption, although I've been trying to cut back on soy as well.

Has anyone else experienced any of these symptoms? What helps? Should I wait it out, and if so, for how long? Should I see a doctor? Please help!