Should i stay in relationship? how do you know if your happy enough?

so m eand ny boyfriend have been together for about 5 months. im 16 and hes almost 18. and i dunno.. like sometimes i feel REALLY happy with him, and love being with him, but like when we are around people hes not very talkative and lively then and its not my thing. im perky. i love him so so much, but its like most the time im wondering what else is out there/ hes serisouly the perfect guy.sometimes im a happy camper but alot of the times i just dont feel like hes the guy for me? is that just casue ima 16 year old girl? or is it casue i know hes not the one? but how do i know if i should stay with him? what is the deciding factors in your relasionthip to stay together? and tellme relationship advice you have if any! thank so much!