My boyfriend [27M] has called off our plans to meet his work colleagues. What’s the best way to discuss this with him without hurting his feelings? I'm [25F].

My boyfriend recently passed a significant exam that he had been struggling with, and I supported him through the ups and downs. I helped him with his revisions, but I never expected anything in return; I was just glad to be there for him. Today, he finally got the good news! He asked me if I wanted to go out for dinner and drinks after work, and since I had a day off, I immediately started getting ready. We don’t get to go on dates very often, and I was really looking forward to it. I even rescheduled my run with a friend so I could celebrate with him. However, a few hours ago, he texted to say he wanted to go out for drinks with his coworkers instead and suggested we could reschedule our date. I expressed my disappointment because I had canceled my plans and was already prepared. He seemed set on going out with them, so I decided to let him go and have fun. I mentioned that I felt a bit like a second choice, but I stressed that he should enjoy himself and we could plan our date another time. Maybe I shouldn’t have mentioned my feelings, since he should enjoy his celebration in his own way, but I couldn’t help feeling a bit let down and insecure. He then got upset with me, saying he felt guilty and that I was making it about my feelings. I apologized and explained that wasn’t my intent, but I thought it might be best to drop the subject so he could have a good evening. I wonder if I should have just kept my feelings to myself. I’m trying hard to be understanding, but this isn’t the first instance where he prioritized his work friends over me, and it hurts. He mentioned wanting to bring pizza home, and I know this might sound trivial, but we had pizza last night and I had already done my makeup, so I asked if we could get dinner instead. He said he would see what time he was done. I'm just unsure how to navigate this without hurting his feelings or ruining his night while also not undermining my own feelings. It feels like he's getting everything he wants, and I'm left just waiting for him to come back. I’m questioning whether I’m being unreasonable or if his actions are unfair. It’s frustrating because he’s been going through a tough time mentally, and it felt like we were finally reconnecting and enjoying our time together again. I appreciate any advice you can share!