I hate my “girlfriend” and I hate myself

I got with my gf (F22) when I (M22) were both 18 we’ve been through it all together, we were addicts, got past our addictions, have lived together, have long distanced the works. Recently I’ve been doing anything and everything for her The past few months If she needs something I’m bringing it, if she wants something I’m sending her money, if she needs me I’m there, there is nothing I don’t do for her but I have found out that she has been cheating on me the past year in a online relationship and was seeing a dude in person don’t think it went to far cause I found out early but idk he said they did stuff, she has been a chronic liar for literally everything she refuses to tell the truth even if I have proof she just acts like I’m wrong I try so hard to move past and let shit be cause I love her more than anything but I’m truly at my limits, I had won a lot of money gambling but when all this started unfolding I got angry and went on a bad losing streak now I’m down 35k with 3k left in my bank and in a weird spot with her today we were supposed to hang out but she called me crying cause of some bs and said her nana who she lives with said no then I see her post on tiktok a hour ago another man he’s gay but that’s beside the point at her house getting his hair done when I have needed her todo my hair for 3 months! I’m so fucking tired of it I’m so tired of her I truly hate her so fucking much but I can’t seem to leave her I truly have an addictive personality and she’s essentially a drug to me and I can’t quit it, honestly I don’t even want to leave I just want her to act right if she would just act right there would be no issues but she can’t she refuses to and that’s The problem she just got into therapy but I honestly don’t think it’s gonna change shit she seemed actually remorseful for a single day and then went right back to her normal antics I’m literally on the verge of losing my fucking mind idk what todo atp I just needed to get the words out of my head cause it hurts my brain when I don’t let it out, for awhile I was keeping a journal and writing down my feelings in it along with drawing which I love I think I’m gonna start that back up can’t hurt anything so yeah atp I’m just tryna not durk my smirk but it’s fine fuckk I’m happy I got some of it out today has been hell like every day is being with her but not seeing her in person