If the time that your semester was about to end coincided with when he stopped talking to the other girl, that may explain his renewed interest.
He now knew that this other girl was unable to give him the kind of emotional boost that he would normally get whenever he was around you.
Since he has shown an ability to talk to other girls and is called a flirt by his classmates, he may have some player mannerisms or attributes. However, he doesn’t seem to be an all out player.
An all out player wouldn’t get as shy, nervous and incapable of talking as he does whenever he is around you.
He may be the type that finds it easier to talk to just about anyone with ease, unless it is someone that he either has feelings for or has complicated feelings for.
In your case, it may be more so complicated feelings than regular ones. Those complicated feelings may be defined by a side of him that would like to talk to you sincerely and another side that just craves your attention.
He may frequently flirt with the idea of talking to you.
However, there may be a certain level of vulnerability that he is worried about experiencing if he were to make a move to talk to you.
He may be putting out this kind of effort on you even though he graduates in 2 months because he is the type who gets even more motivated by a deadline.
If he is able to get the attention that he seeks from you before graduation, he wins.
Though he knows that this attention will be short-lived, it is still worth it to him. It gives him the kind of emotional boost he needs without having to take a chance on talking to you to get it.
Trying with some other girl who would actually give him something in return would pale in comparison to getting your attention.
That would be too easy for him and he wouldn’t experience the kind of emotional boost that someone who was more of a challenge would provide.