I am 15 and my mum has known for years that i like to crossdress?

It has been a kind of open secret between us and over the years sne has either pretended not to notice or maybe just turned a blind eye. Anyway last year i was almost bursting with these feelings of frustration and i knew i had to take things to the next level and one day in a flood of tears it came out in the open as i said it was not a shock for her but it was still awkward for a while. She said that i should not hide it but i should be careful when and where i dressed. This xmas we agreed that i would get clothes and make up etc and i could start to dress at home, i got some fab things for xmas but my problem is i cant seem to get over the inital embarrasment i have yet to dress fully in frontt of her, she is aware of this and has said that as we are on our own this weekend it would be the right time to do it the plan is when she gets home from work i will be dressed and will spend the weekend dressed. I feel amazing and very lucky but as i sit here i feel really sick i have done my hair and make up and am trying to decide what to wear but why do i feel so sick and nervous i have wanted this for years and really want to enjoy it.