Hi Megan
The overriding thing that I pick up from your situation is that you are uncertain about what you want and despite the time that has passed since you moved back, your parents still take priority over your boyfriend.
You moved to your parents not just because you missed them but because you weren't ready for the stage of the relationship that you had. Your boyfriend still has to get on with his life and unfortunately because you are unclear about what you want and your priorities point towards the feelings of your parents, your boyfriend probably has to make the decision that is most appropriate for him right now.
It is great that you have a close relationship with your parents but as you get older and pursue relationships, you need to balance this with your own individuality and your life. If it is absolutely pivotal for you to remain in the vicinity of your parents, then you have to accept that you have two more years to wait.
You need to decide what you want. Is the fact that you weren't ready to live with your boyfriend really about your parents or is there something deeper underneath? The reason I ask this is because if it's not missing your parents, it's buying a house, and with another two years, your life will develop and so will your ties to Arizona. That's good if he does move back in two years, but what if he doesn't?
You need to decide in your heart and soul if this relationship is for you and if it is, you have to meet your partner half way and either let him do his thing in Cali or go to Arizona. You can't have it both ways and I think that under the circumstances, he has been very understanding and you can't expect him to sideline his educational and career goals. Unfortunately whilst he was understanding, you also showed that you weren't prepared to sideline your needs or compromise....and you kind of don't want to now either.
Eventually you are going to have to commit to him and your life together but right now I suggest on focusing on making your long distance relationship work rather than trying to force him to change his life anymore. If it's his dream - why take that away from him?
But decide what you want independently of what you think your parents might think of your or how you think he will react. And remember, houses can be rented out should you decide you want to move! Oh and parents can visit!
Nothing is insurmountable. Commit to a decision and do something.
Good luck!
NML