Oh wow... there's a lot to unpack here @Mumof2girls123 Hope you are doing OK.
I think you have ALOT of decisions to make, and continuing with the pregnancy isn't the most critical right now actually.
There is no such thing as a SMALL gambling problem. It's just a gambling problem. It's only 'small' because you're already broke. I say this as someone who found out earlier this year that my husband is a gambler. He has completely ruined our lives in the space of about 6 months.... because it escalates so quick. The difference is when I found out I took no shit and I didn't make excuses for him like it's a small problem. I gave him 2 options, hand over every penny so I can clean up his financial mess (which will take about 5 years) while he goes to therapy and gets a 2nd job, or he can walk out the door and say goodbye to his family. It's been about 6 months now and I've cleaned up alot, we do therapy together, he's taken up a sport to occupy him, he goes to GA and he has a 2nd job. We are also expecting another baby so I couldn't risk him dragging us further.
You don't have a solid roof over you & your kids heads, and your husband somehow has spare money for gambling? He's not the man you need in your corner.
Accidents happen, probably majority of the population are accidents. I'm.not going to judge that. And terminations aren't for everyone. Personally I'd worry how my existing kids lives would be impacted given they are already in a tough situation. Only you can decide if you wish to terminate or if you can see a way of having this baby.
But please make this decision based on YOU and your existing children and ditch the husband pronto. I think you should talk to housing about getting you & your kids setup, without him.