How do i go about leaving my selfish mother to live her own life without me in it?

i live with my mum, she is a selfish woman and ive had it with her i wanna leave her house but im 19 doing my A Levels full time. I hope to leave for uni next year, BUT I CANT HANDLE LIVING WITH HER ANYMORE. i work 8 hours a week the only time I have free; ma wages are not enough to pay for an accommodation. What other options do i have? shes d only family i have here in the UK.