Weight gain

Today I’m 25w1d and my dr informed me I’ve gained 15lbs since the start of my pregnancy. And recommend I don’t eat a lot of bread,pasta and don’t eat late meals. Only to avoid having a bigger sized baby at my 21 week ultrasound they measured baby at 1 pound and 4 ounces. I eat normally before pregnancy but have added 2-3 snacks either animal crackers (helps with nausea that I still get) or fruit. Also I drink more than 64 ounces of water daily. I work 6 hours 5 days out of the week with 2 days off but on my feet constantly for the whole shift also work late hours 2 days out of the week so I do eat late those 2days. Any tips to keep the extra weight off or easy exercises to help lose weight.