I broke up with my boyfriend of 10 years & need some outside perspective.

I(23f) dated this really good guy (24m) since highschool. Things were great with some minor issues here & there, until last year when we started living almost together. He was caring, understanding, supportive of everything that I do, etc. One major habit that bothered me the most was him consuming alcohol endlessly. This started a year back, when I warned him to take control of his lifestyle and stop drinking or may be once or twice a month. Everytime after drinking, he would become aggressive, fight with everyone around, go on a endless rant about something/someone and generally act like a bum. I explained how alcohol was taking up control of his life and he is becoming a different person. He was sorry and I gave him a chance to be a better person. This happened again in January 2024 and he abused me, after which I said that I want to break up. 4-5 days of arguing and I let off everything go, because of 9 years and I thought things will change. I forgave him and not 10 days later, things went downhill again. He got drunk and told his friend in front of him that he had many better deals than me, but he rejected them because he was with me. I lost my shit and demanded to see his phone. I haven't had touched his phone ever because I trusted him. But when I went through his WhatsApp, this girl (my first childhood friend) who he thought was better deal and him had chats which made me doubtful of them seeing each other behind my back. I asked him, if he met her and I don't know about, tell me right there. And he denied. I was okay with them hanging out as friends do. But why do you want to hide it from me? He said,"I thought, this want that important to tell you." "We were just meeting as friends" "Now that you know, what's the big deal" and stuff like that. He begged me for forgiveness and I did again. Because there wasn't a solid proof for cheating. We have mutual friends & I told them about this. All of them took his side and assured me that there's nothing to worry about and we have been together for 9 years now, so we should try sorting things out and be together. I thought, I am overreacting and let it go again. Things were good for a month or so and he resumed his drinking. I said nothing. I wanted to protect my mental peace. Fast forward to July. On my birthday, he asked me to help put up my story on his Instagram. And I said if I should search a cute wish on Google. When I went to the search bar, all I could see was corn websites. It's my birthday and i was looking forward to celebrating this and the lo & behold....1st hour of my birthday, I was traumatised. I asked him to explain all of that and he had zero answers. I went to history and all 18 days before my birthday, each and everyday, he watched it. I was truly appalled and had no words and just shocked. Since this day, I have been contemplating to breakup and said this to him several times that I am not happy in this relationship. He promised me that things will be okay and somewhere deep in my head and heart, I want to believe him but he has time and again proven that he isn't capable of proving his promises. Am I being paranoid, do I give him a chance or should I go no contact. 10 years is a lot, I have only know this one person for my whole life. Moving on is going to be very difficult for me, but I am not sure of what should I do. I am not in a right state of mind to take decision or maybe I am taking wrong decisions or rushing this. Help me out, please.