What happened? She's died.....
haha
No she's probably not, but the biggest thing is she doesn't view you as important because if you were important you two would remain in contact. It sounds as if she was using you...you said you did all this stuff...that's a problem right there because what stuff is she doing for you? It sounds like you were only doing stuff so right there should have been a sign and YOU also took her out A LOT. It sounds like she's using you for her own amusement.
It's about both of you investing, not just one, and investing at the same level, not one doing everything and the other nothing.
She started ignoring you once for a bit and never apologized. Another thing that is NOT GOOD in my book. She blocked you and things like that for no apparent reason. This girl is the worthless one not you and she's playing a game. If she had any manners she would have tried to talk things out or at least call you up like a grown up and tell you she's leaving you and why. By the sounds of it I don't know if you truly labeled as boyfriend/girlfriend or not in her mind unless you discussed it....communication is key and here is an obvious reason as to why keeping in contact throughout the day is best. In the end when you truly like someone and care about them you want to know what they are doing and you want to have them in your life so that means trying to tell them what you're up to...keeping the contact there and including each other in your lives, not keeping you on the side.
If you don't fit in each other's lives or make each other fit by taking time out and talking then you're already doomed. I hope this has helped quite a bit. All I can say is don't worry or be curious as to why, she's obviously a bitch and unless she died, got in a terrible accident, or got amnesia....those should be the only reasons why she's not keeping in contact. People come and go that's the truth of the matter these days, don't beat yourself up and do what you said move on and find someone who you deserve because you deserved a lot better than who she is and what she did to you. You deserve someone attentive, someone who cares about you enough to communicate through all times...even the hardest of times.
Obviously you were more serious about this than she was and that's the ultimate reason so if you were curious about it...I answered. That's basically always the problem in some kind of form.
If anything goes further south let me know in detail and I'll try to help or if you have any questions

Good luck on your new journey of being a single man, just think now you can do whatever you want, whenever you want and you're saving a lot of time and money spent. You win!