Lost that Loving Feeling

I have been with jen for almost 3yrs now and there is no more romance. I love her more than anything in the world and (wanted to marry her) have not been paying much attention to her because we have been fighting lately. No sex, no romance, no fun anymore. She is distraught over this and poured her heart out to me. I could not tell her how I feel because I don't want it to end. I am her best friend and vice versa, but I have a group of single friends that i have been going out with and she has none and also does not like mine so it's hard to go out together. All I can picture is her crying face like I ripped the heart out of her chest and it's killing me just the same. CAN YOU EVER GET THE ROMANCE BACK OR IS IT OVER.