Am I mad to want another baby before leaving my husband?

[DisneyBaby]

My husband and I have been very up and down throughout our whole relationship, he's always been lazy and not much help around the house, he has a gambling problem which has resulted in trust issues and he can have a bit of a temper with me at times too.
We have been together 10 years, married 4 and have a 15 month old daughter. I have always wanted 3/4 children close together in age so they would have a close bond like my sisters and I had growing up. But I am now pretty certain after deliberating about it for several years, that I want to leave my husband. I do believe I can do better, and a lot of friends and family have told me the same.
I worry that I wouldn't meet someone new straight away and I think about my daughter growing up with no siblings close in age, and it makes me think... Should I just stay for a few months longer and have baby number two so that my daughter will have a playmate, or is that totally stupid? As much as I would love another baby myself, this decision is more based around her, if I were to be a single Mum she wouldn't have someone else to play with at home and that breaks my heart.. Surely I can't be the only person who has thought or planned such a thing??? Am I crazy?

Yes it’s stupid. Having another child with a man you’re planning on leaving just so your kid has a ‘playmate’ is a ridiculous idea. Second/third children should be wanted for themselves, not just so that their older sibling has company

It's funny how you say you could do better. He definitely could after reading your post.

I don't think it's selfish to consider this. I'm a single mum to an only. It's can be very quiet and lonely just being 2 of us in the house. Every meal just us 2, running out of conversation. We see friends but there's so much empty time in between. I work and use childcare so DD feels passed around. It would be much harder for me to have 2 children but it would be a happier family environment.
Having a 2nd with your husband would be much kinder to your first child than forcing a step dad and half sibling into the mix. As another pp said, you would potentially feel time pressure to find a new partner and make a bad decision in the rush. Better to have your family first, spend some time single then calmly find a partner just for you, with no aim to have more children.
That being said, it's only doable if you're financial stable and have people who can babysit regularly.

LikeABundleOfHay

The glaring absence of any concern for ethics in this relationship might be a reason why you say you feel lonely? This is no way to treat people!