I recall replying to this post in Psych Central's relationships & communication forum. I don't know if you're still with us. You mentioned having been bullied in school. I don't know to what extent. But I thought I would mention I was also bullied in high school. It went on for the majority of 4 years. Everyone knew what was going on, including my parents. But nobody cared. And I've struggled with the sorts of things you're struggling with my whole life. (I'm an older person now.)
I think, somewhere in your post, you wrote that you felt you'd be too nervous to see a mental health professional. But I have to tell you that, at least based on my own experience, school bullying can really mess with your psyche. And I don't know how else you "get to the bottom of it", so to speak, unless you work through it with mental health assistance. I never had that because, for most of my life, there just weren't the kinds of mental health services available that are available today. Consequently I just toughed it out as best I could. And it wasn't pretty. So I hope that, in some way, you can find the courage to seek out the mental health services you need. My best wishes to you...