<human>: Condense the text into a few key points

Ive been going out with my girlfriend (she is 17)  for a while now , Im 18 I make her laugh and other things that couples do , we spend the weekend together and have a somewhat good communication. Yet I cannot shake the feeling that I am good enough , that she will leave me and that I will feel like shit. 

I feel like I dont make her happy enough , dont make her laugh enough. Seeing other guys making her laugh makes me extremely jealous. She reassures me that I am the best bf ever and that she would be destroyed if she lost me , but still... Need some help please.
<bot>: =  I cannot shake the feeling that GF will leave me , eventho she says she never will and that she loves me.