RELATIONSHIP HELP!!!!!!!!!!!!!!!?

Me an my girl hav been dating for about 7 months. Recently I stumbled upon her bebo page without her knowing an apparently she been talking to a guy. Ther we're lots of I love yous an I miss yous an stuff. So I talked to my friend an he urged me 2 break up which I had already made my mind up 2 do. The next morning I went off on her in the parking lot an had thought it was over. I skipped a coupl hours of school an she texted me. She said she loved me an wanted me an said that she never met the dude they jus talked an that it was a old friend. So later we talked n person an I ended up taking her bac. Now the next day my girl hates my friend 4 tellin me 2 break up wit her an she thinks that since I lov her that he should hav told me 2 stay wit her. He keeps telling mor an mor ppl an im catchin the heat 4 it. Plus the fact I really lov this girl an will an hav don anything 4 her an she has don erthing 4 me we both r friends wit each others parents, I lost my virginity 2 this girl, an I am the 1st dude she's ever introduced 2 her dad. Her hometown is about 200 miles away an that is we're the dude is at. An I kno when she goes bac ther is no way ill kno wat she's doin. I jus really need advice I feel so bad rit now she says she's sorry an she only wants 2 b wit me an loves me an that shell nevr do it agin but I also hav my friend tellin me 2 forget her. Thers 2 many feelins ther 4 me 2 do it that easily an I don't kno wat 2 think rit now. With her im happy an feel myself agin but wit my friends an mor ppl sayin how they can't belive how I got bac wit her evryday doesn't help an is really depressing. Do u think I made the rit choice? Please help an thank you. O by the way we're both 17