I am very confused. Then again, guys are confusing. Let's start from the beginning...

This guy's name is Jack. I've liked him for 3 years, but year 1 I didn't really make any contact with him at all, so it's not really anything worth talking about.

Year 2, we were really good friends. We always talked in school, we even had a bunch of inside jokes we'd always talk about and laugh about. We were weird together, laughed together, and talked in and out (texting) of school. Yet we never did hang out outside of school. One day, Jack, a friend, and I were talking and somehow the comment came up from the friend that Jack liked me. Being the socially awkward person that I am, I didn't really think that for once, a guy could actually like me, so I just rubbed it off even though his face got red when his friend said that. One of my best friends recently said that it was really obvious that he liked me. But anyways, over that summer, he just randomly stopped texting me one day. I didn't want to bother him any more than I thought I was, so I waited a week to text him "Heyy :)" like I normally did, and he normally replied within a couple minutes. The rest of that summer, he didn't text me once.

At school that fall (this current school year), he have 2 classes together, unlike the other years when we LITERALLY had every single class together. We made absolutely zero contact with each other, except for maybe a couple months after school started, I texted him and we ended up talking about classes, and somehow it came up that he thought a girl liked him and that he thought it was weird, I didn't ask who though, and to this day I still think that that girl he was talking about could be me. We texted maybe once relatively close to after that, and I was one of the first people he told about how he was going to have this giant halloween party, and that I was definitely invited. A couple weeks before the party, there was talk going around about this giant party, and long story short, I thought since I didn't get mine and everyone else did, that maybe he sent them in the mail (and that I just didn't get mine yet), when really he gave them out personally. My best guy friend confronted him about it, and Jack lied to him telling him he gave me an invite. Jack did text me though that I was invited, but he didn't tell me the day or time, but long story short again, I did go, and I talked to him very briefly and he was really shy when we talked. Also, apparently in this past December Jack and my best guy friend were talking, and then out of the blue Jack asked "Julia's a nice girl, right?" and my friend replied "Yep." And another time, they were talking about the people that sit at my table at the time (note: I'm friends with everyone except the snobby, stuck-up girls so I sit with different people at different times; and at the time I was sitting with my friends that aren't the most liked people in the school, people consider them as nerds) and the guys' lunch table was insulting the people at mine, but Jack spoke up and said that I wasn't too bad. Very recently (like within the past week) someone said something really random and weird to us people in that portion of the classroom, and Jack (who sits vertically 2 seats in front of me) looked back at me and smiled, and repeated the statement, and kind of just stared at me. I was really confused, so I just looked at the other guy for a second and shook my head and continued me work. This past Thursday also so happened to be my birthday, and I was praying that he would wish me a happy birthday during the school day, but I just figured I got my hopes up. But on my bus ride home, I got the text form him. I nearly peed my pants I was so happy! We continued on a nice conversation for a couple hours, but then I fell asleep, and he didn't reply when I woke up that same evening. We haven't talked since, but he has seen me being really awkward with my friends when he came to ask my homeroom teacher something and he looked a bit semi-concerned (I guess), but I didn't really care (even though I was dying to go up to him and talk to him).

So I guess my question is, based on his signals, should I even try to be even friends with him again? What ARE these signals? How should I talk to him? Am I being over or under dramatic? How should I deal with this? Should I text him more, and how should I do it without sounding desperate or weird?

I'm sorry for it being really long, but thank you so much for helping!!

Also note that Jack is constantly on my mind. He means the world to me, I get so worked up over him, it's ridiculous. I'm almost always worried about what I look like around him and how I'm acting, but when he's not around I act like myself. Also my face gets really red when I'm around him, and apparently it's really noticeable. And another story really quick: I had to sit at his table with my other guy friend (long story) and most of the time, Jack covered his face, avoiding me and blocking me out of the conversation. But during the lunch, things got really funny, we were laughing our heads off, and he kept on kind of smiling at me. I had major butterflies, it felt so amazing to laugh with him and have fun with him again. Oh my goodness.