I disagree, I don't think you too are perfect together, sorry. For a relationship to last and flourish into happy and healthy reality for both parties, a couple needs to share the fundamentals, as it is these basic values and principals on which we build our relationships.

Your feelings have nothing to with insecurity, or being possessive, its about vastly differing values. Some people can share, others can't. The ones who can't, can't do it because its not the type of person they are, its not because they are selfish or jealous. Its like being right handed, you just are...

You 2 are only 16 and already have differing stances on a huge fundamental, fidelity.

A relationship cannot and will not ever be healthy when 1 partner is monogamous and the other polygamous in nature. There isn't even a half way mark to compromise on, because each will end up harbouring resentment toward the other if they give in to what their partner needs or wants.

Imo, I don't think your bf is wonderful at all. I just cannot describe someone who pressures me into being ok with him sleeping around as being wonderful.

Seems like he's not considering you in this equation at all. He obviously knows you expect him to be faithful, and how having sex with other girls will hurt you, yet he's completely fine with guilt tripping you for it.
That's some shytti non wonderful behaviour right there.

If he was decent, he would respect your feelings, understand that you guys are just too different, and then end the relationship.

But let's say maybe, (a small maybe) he's not a jerk, that still leaves the fact that you 2 are incompatable. He thinks he should be able to sleep around, you don't.

There's just no compromise in this scenario...