How do I (f27) save my relationship with my boyfriend (25) after the mess I created?

Long read
My boyfriend "A" and I have been together for three years. Him and I were supposed to visit a few friends and family members of mine for my birthday/vacation to California. The trip had been planned months in advanced to avoid any complications. Everything was going smoothly until my friend "Holly" decided she would join our vacation for a few days because she also has family in California.
My boyfriend was always skeptical of Holly because she apperantly has a drug problem that she didn't care enough to get help for. Initially, I assumed that he didn't want her there simply because he thought she would be an inconvenience. Holly seemed like a good person and had never given me a reason not to trust her. My boyfriend thought otherwise.
My boyfriend would always tell me Holly was a bad influence and that it wasn't the best idea for either of us to be around her. He claimed she was only pretending to be nice. He said that something always felt off about her. My boyfriend can be cynical at times and I simply believed he was paranoid because he hasn't really gotten to know her.
The arguments between me and my boyfriend began the last couple of weeks leading up to the trip. He kept pressing on about how Holly was a bad influence and not a nice person. I got fed up with it and accused him of being controlling and manipulative (he's not). On the final argument before the trip he gave me an ultimatum; he said if Holly went on the trip, he would stay behind.
I was so angry with him that 2 days before the trip I went and stayed with Holly and didn't answer any of his calls. During our last argument I grabbed my stuff and stormed off. My boyfriend asked where I was going and I replied "to find somebody better and less controlling." He didn't know where I was and I ultimately ended up going on the trip with Holly (HUGE mistake).
Turns out the "family" Holly had in California were just drug dealers. I let Holly borrow a pair of jeans from me and when she returned them...you guessed it, drugs were in the pockets. She tried to get me to do drugs with her and even sell it.
I left home a day later and immediately tried to apologize to my boyfriend, but he didn't answer my texts or my calls. When I got home I could tell my boyfriend had been crying a lot because his eyes were so swollen. He packed a small backpack and left to stay at his brother's for a couple days. To make matters worse, he left a box with the most beautiful bracelet I have ever seen and a letter tittled "to the love of my life." I immediately started bawling because I chose a dumb friend over him.
I feel like a complete idiot for not trusting my boyfriend when he was only looking out for my well being. I regret what I said and what I did. I deserve to be told every insult under the sun.
Please help me. He hasn't broken up with me, but how do I apologize and win his love back? How can I make it up to him for my ****ing stupidity? I'll do anything not to loose him.
TL;DR: chose a stupid drug addict friend over my loving boyfriend.


Source.