I’m so sad right now

I met my boyfriend in 2017 but we started dating in 2018.

We’re both from the same country but he lives in the USA. He flew over here to surprise me on my birthday. He took me to dinner and told me he has a 10 month old son and the baby lost his mum during pregnancy. The lady was his ex, they just had sex. They didn’t have a relationship and this happened way before we started dating even though I knew him by then. I’m so sad right now. I can’t believe he kept this from me for that long. He also told me he wants to marry me. He’s a good man and he makes me very happy. I’m just confused about him right now. I want to make right decisions