Informal Letter help

I'm preparing for the English Olympics by myself and I really need some help.I wrote a letter and if you could tell me the mistakes I made I would be grateful.Here's the letter:
Dear Jane,
I really miss your letters. We haven't talked at all since this school year started and i bet we both have some interesting stories to share. I've had a great year and the best thing that happened to me was the theatre troupe in my high school.
My classmate, Anne Jones ( yes, she is the daughter of the famous actrice) invited me and two other friends in the theatre troupe. I was a bit reserved at first , as I don't like to see a lot of eyes settled on me * I don't like how " a lot of eyes" sounds, could I have used "mob of eyes" or "crowd of eyes" instead?* but,due to numerous requests from my friends, decided to give it a go.
Last week I was informed that I was accepted in the theatre troupe! At first I started to worry * When should I use "started to worry" and "started worrying"?*, feeling unprepared for the many plays I was going to perform in but,when I met my colleagues and teachers, all I could feel was joy.We've made a funny warm-up exercise and the teachers gave us some scripts to learn for the next lesson. It was wonderful and a lot of fun to perform in a play, together with my best friends.I can't wait for the next lesson!
This was the most beautiful experience I had since school started but, a lot more things happened * have happened or happened?*to me. I glued a photo of the theatre group on the other side of this sheet.I really hope to hear from you soon and maybe, you could send me a photo of your classmates.
Best wishes,
Sarah