Too much for me to handle

I'm 18 and try so hard to find a therapy place but got rejected everywhere by now. So many things are going just wrong. At home I have no one to count on, I am by myself except for living with my mum who is often so mean to me. I also do not have an own bedroom and just feel like wasting away with no one being there. I want good grades and want to do well but can not manage, I have ocd symptoms, tics like tourettes and so much else, but all undiagnosed as I can not find a therapy place and have no support.