Am I stupid to go on like this?

My best friend is a guy and we've been best friends for about 5 years, give or take. We've been through a lot of hard times together, the death of his horse that he'd had for 5 years, the death of my grandfather, a fight that broke out between us that caused us to not talk a word to eachother for three weeks. But together we were able to fix everything and make everything good again. Lately he's had major troubles with a girl, he's liked her for about 9 months and recently she told him she didn't feel anything for him, and rightfully so, it crushed him. Well, being the best friend I was there for him. I told him it wasn't him, that he was an amazing guy, that he would make any girl he dated the luckiest girl out there. All of that wonderful stuff. He texted me late night/early morning because he couldn't sleep, and I purposely set my phone on loud so I'd be able to hear it if needed me. I sat up with him just being there for him. This has happened more than once also, because during this whole crush of his, he definitely had his doubts, and I was always, always, always there to talk him out of his feelings of self doubt. It was always just kind of my job to be there, and I never really minded. Until about ten minutes ago. This whole thing with his crush happened Thursday night, and today he was such an to me. I'll also need to tell you this story, and I apologize if this gets really long. I also kinda need to vent, but anyway. For his birthday, I was going to get him two tickets to see the Rascal Flatts. $350 tickets for the two of us to go see since we both love them. He didn't want me to get him such an expensive gift, and it turned out that I had a basketball game out of town that same day anyway. So we just kinda forgot about it, or so I had thought. He went and told his parents about what I was going to do, and they agreed to buy him the tickets. Except now he's planning on taking someone else because obviously I can't go. But when I asked him to ure me that I was the first one he'd ask if I could go, he replied with just an lol. I know I'm probably reading into this way to much. But he does this kind of thing just to piss me off because I'm the type of person who takes things so personally. Is it dumb for me to be jealous about something this small? I mean, I know he wants to go, and he deserves to go, but to take another girl that I can't stand, and to take her to OUR concert, isn't that a little low? Also, with how he's treated me, is it dumb of me to continue to let him basically walk all over me? To add on, I've recently been diagnosed with depression and when I was really sad, he wouldn't comfort me all that much, all it would be is, "It's ok." or "Don't cry." and then he'd move onto something else. I just don't know what to do. He's just the type of person in my life that I seem to forgive because I can't stand the thought of not having him in my life. Is it time for me to move on, or should I continue on with him? I definitely don't feel this way all the time, but when I do. It kills. And yet again, I apologize for this being so long. Please help!!