Please, any advice welcome, struggling.

Morning. I am a mom with a teenager with autism. Academically she is good but socially things are getting worse. She also has PAD which is proving very difficult as we enter the teenager years. She is now a school refuser and things are progressively getting worse at home. She is sleeping til 2pm everyday day. Refusing to get up any earlier. She doesn’t want to go out. Doesn’t want to get dressed. She says her clothes look awfuL on her and is trying to not eat some days. We are due to go on holiday and she won’t shop on line with me for clothes and is currently saying she isn’t getting on the plane. She speaks to me like I am dirt on her shoe. She has masked for years but I feel the mask has come off and now she can’t mask anymore? 

my question is, will this get easier and what can I do? 
should I be allowing her to sleep so long? how can I encourage her to get dressed? Are there things I could put in place to support her better? Encourage her to leave the house? I am and have tried lots of things and I work in SEN but when it’s your own daughter it’s a different situation completely.

please help, I really am worried and struggling,

thank you