I'm feeling uncertain about my boyfriend, who is 22 years old.

I'm not quite sure how to start this, so I’ll begin with a warning: this will probably be lengthy. My boyfriend and I began dating at the end of our senior year of high school when we were both 18. After a year of dating and visiting each other at work, we began discussing the idea of an open relationship, or the possibility of adding another girl to our dynamic. I identify as bisexual and have never been with a girl before, but ultimately, we didn’t pursue it because I felt too insecure. I worried that if I let him explore that avenue, he might find someone better and leave me. We decided to continue our relationship without pursuing that. We moved in together nearly a year ago and have been together for almost four years now. Recently, we revisited the idea of an open relationship or including someone else in our intimate life. We both downloaded dating apps to explore potential connections. However, while I received numerous messages from guys, he engaged in only a couple of conversations with girls. This hit his self-esteem hard, leading him to feel depressed and unattractive. One night while hanging out with friends and playing drinking games, the atmosphere escalated to a point where we ended up in a foursome. This happened a few more times, but one evening, he left the group, claiming he was going to bed. Later, I discovered a series of missed calls and texts from him, pleading me to stop what was happening and come to the bedroom. I hurried in to find him sobbing on the floor, feeling abandoned and alone. I was drunk and upset because I never intended to hurt him. He was so distraught that he punched the concrete floor. We decided that this type of situation wouldn't happen again. After that, he stopped using dating apps, feeling unattractive, which led me to delete mine as well, especially since I felt guilty about having so many messages from guys. For context, I had never met up with any of them and only replied to a few, as my priority was always him. Recently, he’s started using the apps again, which makes me hopeful that he’s feeling better about himself, but he also experimented with mushrooms. He tried them for the first time on a weekday after dinner and seemed fine, but when Sunday came around, things took a turn. I was about to make my usual weekend coffee when I realized I was out of supplies. He offered to accompany me to Target and mentioned he wanted to take mushrooms beforehand. I told him no because I was concerned they might kick in while we were out. He agreed but said he would take them once we arrived. While we were shopping, I noticed he was chewing something and remembered his plan. He started getting snippy with me in the store, and I felt frustrated by his attitude. After we returned home, he asked what was wrong, so I expressed my feelings about his behavior during our shopping trip. He apologized, saying he thought we could make it quick. A few minutes later, I heard him groaning and found him on the floor, feeling nauseous because he hadn’t eaten before taking those gummies. Unfortunately, this led to a rough couple of hours filled with groaning, vomiting, and discomfort. He eventually managed to sleep for about three hours, and I stayed with him, anxious that he might choke on his vomit. With just two days off a week, I was looking forward to spending time how I wanted. I felt frustrated because he had set up plans with a friend on Saturday, which limited my free time. I don’t want to take on the role of a caretaker for an irresponsible partner. I’ve previously mentioned that I don’t want children since I’ve already raised my siblings, and he understands that. I might just be feeling burnt out from work or overly emotional about everything. It could also stem from my jealousy that he gets to work from home while I'm stuck in a hot kitchen for over eight hours a day, then come home to clean and cook. He has supported me through so much and has been there for me as best as he can. We love each other, share two cats, and live in a tiny apartment together. I don’t want to end our relationship, but I’m hesitant to bring up the idea of an open relationship again since it could trigger his depression. He’s struggled with suicidal thoughts in the past, so I’m genuinely confused and saddened by everything. I know a difficult conversation is inevitable, but I tend to get emotional during discussions, often crying regardless of the topic. I’d appreciate any thoughts or advice on my situation. Am I the problem?