Having kids is not for everyone. I noticed how much of a toll it seems to take on Westerners, but for the Asian/FOB folks that I know having kids doesn't phase them at all. They live virtually the same lives they did before. My bro and I are white-washed Asians/coconuts (brown on the outside, white on the inside) and he just had his second daughter and it didn't phase him.
Only thing that changed was that he had to structure his days better and couldn't just fuck off to the gym anytime he wanted. Sometimes late nights if the kid's up screaming or shitting themselves in the middle of the night, etc. I've seen people have a kid and conversely need to take stress leave from work, they look like shit, get fat, depressed, divorce, etc. I never see it with the FOBs I know though. Just visited my new baby niece and my little brother is pumped. Their kids luckily sleep like angels, but even during bad spells he'd just take a nap during his lunch break at work or make sure to dial in his diet and eat well.
I'm having my first kid in November and I'm absolutely pumped. Gym's close by, they've got child minding available, got lots of family to help out, might start working from home full time, etc. The fulfillment you get out of it is completely up to you. If you let difficult situations ruin you, a kid will fuck up your shit. If you're able to take hardships and setbacks in stride and find appreciation in the things that matter, then having a kid probably won't be so bad.