First time sahm help!

So my fiancee is a rockstar. We have came a long way 7 years together 3 beautiful children. Now he has his cdl working for a great company. And now i am a sahm I feel like i am going stir crazy. I have no friends because we had kids young and they could not relate. I am getting enrolled in college for nursing to finish up my degree finally so I feel like that will keep me busy but I am always at home taking care of my children which I don't mind until I don't get a second to breath it's a 24 hr job. I already knew that I was working 16 hr shifts pregnant and taking care of my other 2. But at least work handed me a little time to relax when I was on break. What do you guys do to unwind and everything? I am trying to figure it out.