exercise 😓

Janine 🇨🇦
A little back story, I use to weigh 56kg. When I got pregnant with my now 3 1/2 year old I went up to 84. After I had him I lost 18 but when he was 1 I got pregnant again with my soon to be two year old and went up again to 85kg. It was a long journey but I made it down to 65. Me and hubby decided to start TTC again and while I eat healthy, drink mostly water and walk everyday (with the kids) I'm finding it extremely hard to lose anymore weight. I'm currently 157cm so I'm considered overweight and I'm afraid that when I get pregnant again I'll go back up to my previous weight. It's hard for me to go to the gym, I don't drive and by the time I'm done work and the boys are in bed I'm exhausted. 
I'm kind of just looking for any advice.