Why do I have a compulsion to find a girlfriend online?

Am I really that desperate and lonely? I feel so perverted and embarassed by it. My parents are so anti-dating culture and think that if I have a girlfriend my grades would be ruined. It's quite the opposite, on the contrary. I feel like my grades are slipping because I masturbate a ton (which makes me really lethargic and unmotivated), which in turn is a result of my anxiety of starting any task and my loneliness. Yeah, I have friends at school, I can talk to boys and girls without feeling super anxious, but yet I feel so lonely. I've had some really specific fetishes that nobody I know in real life really fit. I'm so desperate that I feel like I need to loosen my standards. I just need somebody to tell all my problems, big and small, without them having to judge me. But yet, I still want to find "the one". As much as I want a temporary relationship to ease the loneliness, I don't want them to go away with my secrets. Just somebody that I can feel okay with fantasizing cuddling. What's wrong with me? If my parents found out I had a girlfriend, they would get pissed at me (and it's happened to me before and my parents still nag me about it). They say it's normal for a 16 year old, but I turn 17 in January so my birthday is coming soon. Why aren't I maturing? I look, act, and feel 12 still. What is wrong with me? Why am I so obsessed with wanting a girlfriend?