Just feeling really defeated

Kellen • Pregnant with baby #1 after months of TTC and large weight loss. Hubby and I couldn't be more excited!
Morning ladies :)
So the past week I have ballooned 8lbs. Everything is swollen, face and feet. I'm 18 weeks as up until this week I had managed to not gain any weight. Then one morning I step on the scale and it went from 281 to 290. I've been eating right, even walking 30 minutes a day. My husband and my mom tell me not to worry, that gaining weight isn't a big deal. As someone who worked incredibly hard to go from 363 down to 280 just to get pregnant it's incredibly hard to see that jump. But more than that, it's my fear and absolute certainty that I have or will develop soon Preeclampsia. And I know excessive short torn weight gain is a sign of that. Labor has always been a terrifying thought for me even before I was pregnant. Everyone says I'm going to be ok but I just can't stop this awful nagging feeling that something might go wrong. Sorry for the heaviness, just had to get it out.