i won't lie, it's not easy. i did the same thing at 17-18. while i had just over a year of hrt below the belt by the time i had my first day of university, it seems like you're going to have almost as long to do that. and honestly, i really can't underestimate how much of a difference it makes in how people see you. my world turned upside down overnight, and that can be its own turbulent affair. it can be done, but don't beat yourself up over it if you don't feel ready for it when the time comes. most schools will let you take a gap semester/gap year, and that might be a big help if you're feeling like you have too much to do in too little time.
(another thing you should think about with regards to srs specifically is whether/how you're going to have a place to do your dilations. if you're going to live in on-campus housing, you should try to get in touch with the housing dean earlier rather than later to get accommodations in a private room with a private bathroom; most schools have a determined number of these as accessible rooms that don't usually get filled completely. if you're off-campus and going to have an apartment this is less of an issue.)