Any ideas how to maintain sanity?

First time posting here, so I don't really know the rules and whatnot for posting but anyway, Looking for any kind of input because I really think I'm going to go batshit insane. I have a 4 year old girl, a 3 year old boy, and due next month with another little girl. (Last kid I'm having.) Up until about a year ago I was working full time but had to quit and stay home because the person who used to watch them for me couldn't do it anymore and the idea of affording childcare for the two is a joke. So I've been a stay home mom and taking fulltime college courses online since ya know, no way to go sit in class with them. My boyfriend works full time, I have no social life. Not much interaction with relatives. No "support system" as far as the kids go. Lately I just feel lonely, tired, trapped at home, and generally pissed off. All. The. Time. My kids are always yelling or fighting or doing shit I ask them not to 100 times a day. Or just, being loud typical children. There's no such thing as peace and quiet. They're really not even bad kids but I think theyre bored, and im too burnt out to try to entertain them 24/7. I'm running out of patience and nobbody knows how i feel except my boyfriend and there's only so much he can do since he works all the time. I feel like a shit mom for feeling the way I do, and I just want someone to tell me how the actual fuck to get a grip and find some balance before I lose my shit. How does one do that with no way to ever really be alone? Anybody else felt like this? How do you keep your shit together? Sorry If this post seems like jumbled ranting or parts don't make sense, I could elaborate further but I'm trying to type quick and someone is yelling "I'm done" from the bathroom. via /r/Parenting http://ift.tt/2h62qfD