Pregnant and thinking of separating

I'll try to keep this as short as possible.

There are a few things that I just don't like or can't accept as part of a marriage.

One of them is a husband who stays out drinking past like 1am.

It just is a real deal breaker for me.

My husband has a single friend who is the same age as him (mid-forties).

He has no proper job, and comes to town every so often for I don't know what reason, but wants to party at any random time.

Clearly all of his other friends don't live this lifestyle, so he calls my husband.

My husband and I argue about this every year.

He goes out, parties til past 3am whenever his friend calls when he is in town.

It's an ongoing issue.

Now I'm 6 months pregnant after trying for a number of years.

He goes out last night with this friend and some other guys we both don't know.

He sends me "sweet" messages to basically pacify me saying he's with the "boys" (eye roll - he doesn't even know them).

Then 2 am rolls around. I call him. I ask what he's doing. There's loud music in the background and he replies, "partying."

I said it's enough. It's 2am. Get home already.

His defense is that there are no girls, so he's "not doing anything wrong."

I can hear the music go off and people leave, so I'm assuming they hear him arguing.

I hang up.

He calls me with his friend next to him.

It's like 2:30am now.

I told him I'm sick of it. Grow up. I can't stand how immature and selfish he is.

He's still arguing as if he's not doing anything wrong.

I couldn't sleep until 5am. I'm exhausted.

I'm so fed up with this, especially now that I'm pregnant, and the baby feels what I feel.

I want to separate.

He's not changing.

I feel like it's something simple and small that he can and should do.

When not pregnant, I don't "party" until the morning, so why should I have to put up with it.

Is it insane for me to try to get my own place for at least the few months until the baby comes?

I just don't think it's healthy for him to just disrespectfully, with no regard for what bothers me, keep repeating the same thing.

His friend is still here. Guaranteed he'll do it again in the next few days.

I feel like I'm pretty reasonable person.

Thanks for reading and for any thoughts or advice.

EDIT:

*There are other issues as well:

He's not working, so I'm supporting us.

He's also just 24/7 on the phone with friends, and he'll drop what he's doing with me to go hang out with them at any time. I've asked him to prioritize me a little more than his friends, and he said he'll try to be better, but then he does this again.

And, this friend does more than drink alcohol.

He also wasn't like this during our whole relationship. He was never a drinker/partier. This is new. He's been having some kind of midlife crisis for about 5 years, and I've patiently tried to stand beside him.