I’m just too nervous...

Basically I’m 13 almost 14 and I haven’t had my first proper kiss (with tongue) me and my bf tried it and I was way to nervous and it didn’t work like we just ended up kissing normally, I kinda feel pressured and he keeps making comments about snogging but I don’t really want to do it now, I feel bad because last time we went out i said I wanted to but now I don’t, do I tell him? Do I just keep trying? It kinda feels forced and not natural :(