Hi, I'm new and I have no Idea what I am.

So, I haven't been on a forum in a few years, sorry if I do something wrong.
It's really cool that there's a place online where I can be myself, but I guess I don't really know what "myself" is, so I came here to ask.

I don't know if I'm bi. I've said I'm bi to a couple of friends, but I just don't know anymore. I do get attracted to guys, but recently there's been a kind of pit feeling in my stomach, where even though I am attracted to guys, I feel a bit off? I mean, I still like guys and fantasize about them all the time, but sometimes I just feel weird about it.

And as if that wasn't confusing enough, sometimes I'm not attracted to one gender, where one day I only like girls and the other guys, and sometimes neither, and sometimes both. I find it unbelievably confusing, and I'm always questioning whether I'm actually straight, or gay, or neither.

There was a forum earlier about a guy who thought he was bi, but didn't like men? I do like men, a LOT, and usually I'm not attracted to women, but my sexuality is everywhere nowadays. I almost feel sick thinking of women, is that weird? I still get attracted but I also feel like I want to vomit. Ok that looks pretty weird reading that back.

I really fancy this one guy, and I get really anxious around him, but not in a "I feel real threatened" kinda way, like I'm scared of what he thinks of me. One time I had to sit next to him at a meeting and I was just so aroused (he was biting his nails or something) and really embarrassed. Just seeing him next to me set me off on a million different fantasies, and his good looks were just worsening the situation. It felt good I guess, my stomach didn't feel weird. idk anymore.

yeah so I went on a little tangent but how do I know exactly what I am, or what I like? And should I be writing on a forum or should I just find a therapist/counsellor and ask them instead? I'm a bit wary of using the internet because I had some baaad, unhealthy habits of attention seeking, self-upvoting, obsession, etc. Sorry again if I said something wrong, I'm new here and I don't mean to offend anyone!