My bf of 2 years just told me that he has two kids, what should I do?

I say stay. It's obvious that you love each other and from what you say he loves his kids. Was it wrong to keep it from you for so long? Yes. But would you even have given him a chance if you knew he had kids? No. You would have missed out on him altogether. At your age, no offense, not many guys are going to be single and have no baggage. I don't even consider kids baggage because that word sounds so negative and kids are amazing. I think you guys can make it work. At least try.