You're supposed to rest your body for 18 months after the first child before you get pregnant again!

It's up to you if you want to be a single mom of one or two kids. Since it sounds like the father will just be a child support check.

Bring them both into the house hold and have 3 incomes!!!

It really sucks that your husband cheated on you. That's awful. But if you didn't want a kid you should be on birth control and using condoms. If you are them your life sucks. If not you do deserve the pregnancy, not the cheating.

Then*

I’m assuming that they are not married. She refers to him as partner. That makes it even worse.

What a difficult and heartbreaking situation, OP. None of us can advise you on whether or not continuing the pregnancy is the right choice, but either way, I hope you and your 10-month-old son have a good support network outside of your husband. You didn’t deserve any of this.

The only good news here is it sounds like your partner is a toxic person anyway and you're far better off getting him out of your life.

He's in her life forever, they have 2 kids together.

He's in her life forever, they have 2 kids together.

He's in her life forever, they have 2 kids together.

People starting their comments with "you're supposed" should keep their thoughts for themselves, they bring no solution to the situation.
It is not a general rule that you must wait 18 months before a new pregnancy. Your body can be ready sooner.

Anyway OP: I hope your partner will understand his priorities. As for such few months between two children can be very tiring the first years (it is also a good way to get done with it at once) but it can also created a wonderful bond between the siblings.
All the best.

Solution? It's an online post, where nothing should be taken serious

Your partner sounds like a dink.