Bottom line? You are 18 years old and have a long life ahead. Why saddle yourself with a tumultous couple with a toddler and a soon-to-be-newborn so early in your young adult life? It sounds messy over there.
Especially when you already are feeling this:
It started of hot and heavy like any relationship but now its pretty much reached a dead point.
I just want to fix this relationship and end the stupid issues we keep having. I love them but sometimes I get to the point of saying, I can't take the bull shit any longer and I need an out. I love them both, I solemnly swear, but at what point is Samantha's pathetic fire starter arguments not worth it. If I can't keep her happy and am always wrong when do I throw in the towel and say it is over?
Sometimes it is safer to Love from a distance and break up because up close the relationship is just not good for your short term or long term healths in all your buckets -- mental health, emotional health, physical health, and spiritual health. Love doesn't automatically equal "staying-ness."
You are responsible to you, and that includes the company you keep. If YOU do not put your own oxygen mask on and look out for your best healths, who will?
In this case I think the short term UGH of a break up is less stinky than never ending stinkage from staying in this situation. If you want to try to cope with the jealous, perhaps some of this will help.
But it takes all parties putting in effort. If it's just you -- it probably IS at the dead point. One person alone cannot keep a thing going.
If you feel done here, throw in the towel, heal, and then reach for your next future happiness when you are ready.