D.K.
Nursing is a great career. You will have many options. Hopefully you are getting your bachelor's degree in nursing. If not, I urge you to think about it. I am currently a nurse practitioner. I have known many nurses with AA degrees and when they wanted another type of job in nursing it required a bachelor's. It's hard to get through nursing school now, it's even harder later, but not impossible.
My philosophy is that I can do almost anything when I know there is a time limit. This period will be difficult, but you and your family can do it! You are very fortunate that you have family members to care for him. It's a wonderful opportunity for him to develop relationships with them.
My advise, for whatever it's worth is - let him know each week who will be caring for him. (it's amazing how much they understand early). For example, You will go to Aunt Mary's and sleep at night there. In the morning you will go to Aunt Jane's, ... After you have slept at night (so he doesn't think naps count). I will be home. Talk to him weeks in advance how you are learning to be a nurse and you will be gone four nights learning how to be a nurse. Let him know when it starts. Maybe use a calendar and count down the days. Expect him to be mad at you when you come back. Let him know it's ok to be mad that mommy has to leave, but mommy loves him. Expect his behavior might be difficult for you - just remember this is temporary and it's best for him and your family. Don't slack on the discipline (you may be tempted because you feel guilty. Not saying you should feel guilty. Just saying you probably will feel guilty). You will do him a disservice in the long run if you slack on the discipline. I would also buy him a special stuff animal that you give him and let him know that the stuff animal will be looking over him for you. Sort of something he can hold onto when he misses you. Never can tell if this will help. Don't think it can hurt. In the long run this is harder on you. Try to focus on the good. It's really a very short period of time in his life. He has an opportunity to develop special relationships with family members. If this happens it could be a great thing - can't plan these things. All the best!