Losing my girlfriend, Anonymous (17)

Where do I start, one of my best friends let’s call her Katie id known her ever since 5th grade? We were good friends until we both realized we were fond of each other in sophomore year. I had such a great connection with her, we’d always go down to the beach, drink our hearts out, and just have a blast. Wasn’t until a nasty weekend during the summer before senior year. We were arguing she thought I was cheating cause I would lie where I was when I was planning a little thing for her with another friend of mine who happened to be a girl. Checking the snap map and seeing us together when I would lie to her about where I was. God, I’m an idiot. She was ballistic and was threatening to end the relationship so I told her I was planning a surprise for her. She didn’t believe me which escalated the argument. I’ve been in a lot of arguments and always stood tall but this time I just walked out. Why did I do that? I shouldn’t have walked out. My friend invited me to a party that upcoming Saturday saying that Katie was going. I didn’t want to I just spent the night in my room drinking away my sorrows. When I got a call from her asking for a pickup and she wanted to talk. I told her I would talk in the morning when she wasn’t drunk. She hung up, not knowing that was the last time I would hear her voice. She overdosed on coke that night. When I heard I jumped in my car and sped off to the house. It was already empty most people left and the ambulance was gone. 3 weeks later a funeral was held. Her parents didn’t hate me as I couldn’t control the situation. But I think that if I just talked to her she wouldn’t have done the coke. I don't know, it stills tears me up.