I felt constantly nauseated from weeks 5 to 11, and I never actually threw up. I never took any medication for it, but I discovered that ginger ale was a magical elixir that worked for about 3 hours. Some women get no pregnancy sickness, some experience it their entire pregnancy. But most do not

But, frankly, it sounds a little soon to be worrying too much about hypothetical concerns regarding pregnancy.
I second the advice of counseling, especially if having children of your own is important, but terrifying, to you. Do you have other fears regarding pregnancy, or is it primarily the nausea? Remember, there's a big difference between thinking about pregnancy and actually being pregnant, so it might be best not to over think it. I'd also recommend couples counseling in the event that you get to a point in your relationship where he's pushing for kids and you don't feel ready.
I've been telling myself for years that I want children; now that I'm pregnant, I'm in a constant state of shock and disbelief (I'm 8 months, by the way). The idea of it didn't start to scare me until I was in a position to be pregnant (i.e. married and discussing children).
It's good to discuss these things before taking big steps in a relationship, to be sure you're basically on the same page, but that doesn't mean you need to start fretting over the details of it. 5 years is NOT a big age difference (my husband is 14 years older than me), and 35 is by no means considered old for a man to be having children. You have plenty of time to think about and digest this, and you are in control of when this actually happens to you. Don't forget that