Hey Dani -
Your story is EXACTLY the same as mine. Did rhythmic stretching in my room for 6months (Mum wouldn't let me do it), so got flexible. Was terribly terribly nervous to ask my mum whether I could start gymnastics again (I thought she'd be angry because I wouldn't make the Olympics) at 13. She was convinced I'd get hurt.
My advice: Keep at it. Work really hard at the strength

It's really really really important. I remember the days when I couldn't do one pushup, or I felt like I was going to die after 20 Vsnaps. Now 100 is not too much of a problem
And ice is your best friend when things ache!
You'll find beam easier too because of rhythmic.