How do you move on after being in love for 14 years only to be heart broken and singled out?

i really don't know where to start i've been with this guy for 14 years i really loved him and i still love him. anyway its been a year now and i met this guy he came on to me pretty strong he found me stunningly atractive we've been talking for 3 1/2 months now but i just can't get into him because we have nothing in common and my ex is always on the back of my mind i kind of feel like i'm cheating this guy tells me he loves me but in all reality i'm not feeling him but i feel alone without him even though we have our differences. its like he's feeling that empty space for me but i don't love him i feel guilty. what should i do???