Is my sex life good? im jusr worried my gf doesnt like sex much and that im not good at it?

-so im 18 years old and i have had a gf for 2 years and have gotten each other promise ringd ro stay together and get married. Im just scared that im not good in bed or last long enough and when i ask her she says its perfect im just scared that she is too nice to tell me the truth and woulndt want to hurt my manlyhood, i last about 30 minutes with penetration and another 30 minyutes with foreplay. so is this good or do i need to rtry something new btw we are spontanious and do try different things i just want to know if i need to last longer or what's up? and no size isnt a problem just want to know if i last long enough or do i need to last longerlook up some thins like a g spot,, find out if she likes clit stimulation or g spot stim.. i dont wnat to get to much into it but talk to her. and find out..