Degrees don't hurt but its more the experience and connections you will make with fellow students and other professionals in your area that will help propel you to the next level. Music school is where you will gain this experience and connections. If you are looking for a technical career in music no one will ask you for a copy of your degree as long as you know what you are doing. YouTube will only get you so far as far as technical know how. There is also a lot of misinformation on youtube.
There is a lot of great schools in the Boston area and I'm sure you could find one that was affordable for you. Check out Berklee, Emerson and New England Institute of Art to start. They also have online classes as well but nothing is quite as good as a classroom setting. They will also be able to put you in contact with internship opportunities which are invaluable.
Being a successful rapper/producer is not an easy thing to do so make sure you have back up plan working in music. Maybe you could do live sound, learn mastering or record other artists while working on you rap career. Hope this is helpful!