You might not get any sickness with my first I was sick everyday he's 14mouths now and I'm 32weeks with my 2nd and have no morning sickness. The thing is you are going to get stressed out and as it goes on you will be more tired. I'm tired alday everyday but I'm sure 100% it will be worth it. Please ask for help take the odd day on your own to sleep or just go and get an ice cream. Your first is just at the pushing boundarys time.
Try not to stress about what has not happened yet. Tell your concerns to your friends, family, partner, partner's family, neighbours etc. basically anybody who might be able to help mind your son if you need a 2 hour nap or something. Women who have had children will understand how difficult it is for you and help if they can.