I think im narcissist?

im 16 and a male. and lately ive been dateing. and i dont feel anything...and ive dated differant girls and with all of them i dont feel anything...not even puppy love. so i did some research on the internet and it seems like im like this. when someone is haveing a problem i dont really care i kinda just listen and try to talk to them and seem like a nice person..but i dont care at all..i am not a mean person at all..i am probably one of the nicest people you will ever meet. ill do anything for my friends..but only to make them like me more as a person.. i dont care that they are having a problem...and lately i feel said cause my girlfreind keeps saying she loves me and all this stuff and i hate it when she says it cause i feel nothing.. what can i do?? or is this just a teenager thing?