I felt exactly the same after finishing G Senjou a couple of weeks ago. It takes a few days for all the feels to go away but man you just get emotionally invested into the VN... thats the sign of an excellent VN in my opinion. As others have said, Sharin no Kuni could be an option. Its made by the same publisher/developer as G Senjou. Badass protagonist, good music, a mix of comedy and serious moments, and a couple of twists along the way. After playing Sharin no Kuni, immediately play the fandisc.. it shows you the back story of one of the main characters and its an excellent prequel.