I’m awkwardly anxious around the opposite sex

I’m a twenty year old male student living in southern Germany and I’m awkwardly anxious around the opposite sex. You see, throughout my whole school time I was subject to bullying or being made fun of. I never managed to stand up against it or somehow manage to build up some self-esteem. Instead most of the times I started to isolate myself and even started to see those who didn’t have anything against as enemies. That was up until the twelfth class when I finally got into a class where nobody would bully anyone. However throughout all the time I was bullied, while others where gaining experiences with social interactions, the opposite sex, making friends, relationships, sexual activities etc. I never gained any experience since I was usually scared of others or isolated myself. I’m still a virgin and I’ve never had a relationship with a girl. I was only friendzoned a few times or getting ignored or being made fun of by girls which at some point just made it an agony when I felt I had a crush on someone.

Now this girls I’m into right now is new in our class and often tried to talk to me. But every time she tries to talk to me me throat just closes and I barely get out any words to talk which makes it always so awkward. Well, at least she always smiles at me when she sees me... How can I control myself and manage to have better conversations with her without almost hyperventilating when I see her?