He cheated & lied in the worst way possible way 💔

We been together for almost 5 years and i guess late 2018s he met a girl at work and they started talking then hanging out a lot times.. dam no wonder why he would say he would sleep so early like at 8 pm bcs he “was tired “from work ,but i guess it was bcs he would leave with antother.. we didnt live together until i had my baby so i never knew ...well from all those times they hung out he got her pregnant first while he was with me while he swore i was the only while he said he only loved me while i tought his lips his body his heart and all of him were all mine 💔it hurts how bad he lied how he would go fuck another then the next day see me and kissed me like nothing happened💔.. well its 2020 now and i just found out about all of this . We been together all this time and yea i even got pregnant and now we have a 5 month old baby. He swears he has always loved me and is sorry for everything . He is now begging me & crying to not leave & that wants to still be that little family we were. I messaged the girl & she toldme she never knew abt me until she get pregnant and thats when she didn’t want to know nothing abt him and wanted him out of her life. She sent me some msgs they had from may 2019 which she confirmed it was the last they spoke and he begged to see her & would say that he missed her. I showed him but he was like i only wanted to see her bcs i felt bad for her bcs she waas pregnant w my baby. Ugh idk how to process all this its too much. I really did love him and sadly i hate that i still do . Im just writing all this bcs i have no one to pour my feeling too i need someone to tell me pls dont be stupid ... oh and not only that but he recently started talking to his sister in law sister and they also started hanging out and ended up kissing and flirting in msgs.. HE doesn’t want me to leave and says that he will change and that i can even have all his passwords and phone all the time, but i think that would be to stupid of to accept being with him after all of this .. this hit me soo bad that i am in shock , i cant even process all this emotions i cant even cry all i do is stare at a blank space where i can feel my heart burn in pain. I never thought he was like that. I was so used to being with him this is so hard