Although I have God in my heart, I feel lonely at times?

Im a devout Christian, and I accepted Christ as my savior like two years ago. I pray and read the bible daily. Overrall, I would say I have a good relationship with him. But as of lately Ive been felling really lonely, speically in school. Im a junior in high school. Im kind of shy, but I can also be outspoken at times I have friends that Ive known from previous years, but this loneliness just started hitting me. Many times, I spend times just by myself in the halls and such. I try to make new friends, but it seems so hard. I always have to go up to people, cuz they dont talk to me(unless Im with my friends).Same thing when I see gf/bf couples in the halls. Ive never had a gf, and it feels as if Im missing out. I try talkng to girls, but they just ignore me the next day. Anyone please help me here??