Serious relationship advice?

Ok so im 20 years old and I live with my gf. I work over 64 hours a week and support my gf who does nothin. We argue alot and she is really jealous all the time if she thinks a random girl in the store looks at me. So needless to say im not that happy. She has no place to go except if her mom drives hours n gets her which I dk if she will since she kicked her out. I dont wanna hurt her but deep down I sorta wanna split. To make things more complicated there is this older woman( almost 40 I think) at work who I always thought was sooo beautiful. I recently became friends with her and told her I thought she was beautiful but pretended I wasnt hitting on her and stuff. She said thanks and that it was sooo sweet. She texts me often and says were going to be great friends and that she doesnt reAlly see my age when being my friend n talkin to me which she said she enjoyed after the first time we talked. She dont have alot of guy friends I.dont think so I dk if im in the friend zone or not. do you think I could be with this woman?if so should I persue this and leave my girl. If so how should I go about getting her? I need help badly cause I cant get her out my mind yet I dont wanna hurt my gf. plz help. Be mature anc helpfull plz