what you're describing sounds a lot like what my bf's sis goes through. there is NOTHING wrong with trying to take care of yourself and your priorities first. anyone who makes you feel like shit for trying to accomplish your goals is themselves a piece of shit. school is HARD, and it gets even harder when you're juggling a full-time job.
but you sound like you know what you want and are willing to take the necessary steps to achieve it. don't feel bad for giving a firm NO to those people who are trying to distract you or pull you in a thousand directions at once. and then when you have that degree, you can slap them in the face with it