Should I carry on?

I think he's given you his answer.

What would your ideal look like at this stage?

Two and a half months and what exactly do you want? He seems perfectly sensible taking it slow and so should you.

What does he mean when he says controlling? Does he mean actually controlling, or is he talking about things that are perfectly normal expectations when you are in a relationship?

2.5 months is really not enough to know whether you want to be with someone long-term! They knowthe fancy you, genreally like you but they don't you that well, and it's the lust-based 'honeymoon' period for at least 6 months!

You are 2 months in. What "answer" do you want him to give you? What "limbo" are you in?

Ask yourself what you actually want, and then ask yourself why you want those things.

Run.

That comment about women being controlling is a massive red flag.
It is completely acceptable to broach the topic of whether or not you are official or at least, going that way after two and a half months dating.

He is basically saying to you 'stop asking me because it's controlling'. It isn't controlling to want to know where you stand. And the 4-6 months comment!? Yeah, that means 'I want to screw people for another 4 months, you better be cool with that'.

He is stringing you along. Ding dong ditch him.

He doesn't want to be tied down

If he really liked you he would say "I really like you and I'm looking forward to getting to know you more" or similar, because he would not want to risk putting you off.

As it is, he is saying you are an option and he doesn't want to commit. You fit for now for some reason, possibly companionship, probably for regular sex.

He is not lying, at 4-6 months when you ask him again the reasonable question if he likes you, he will end it...as he will see this as you being 'needy' and controlling.

I'm balancing on this one. 2.5 months is early, I'm thinking that maybe as you have kids it's you that should take things slowly. You've not given full context about the relationship discussion and how either of you view what it means. Was this essentially a discussion about exclusivity? Is he being exclusive? If he is, but not yet sure about giving it a relationship title, you have more time. Has he met your kids yet? Do you behave like a couple yet?
Also, a bit odd his excuse, he could either genuinely have met some particularly controlling individuals and is cautious, or he has formed a belief that women are generally controlling which is a concern and shows a poor attitude to women generally, so beware of that. Given some time and thought, the answers will arrive I think.

He said he's of course not seeing or dating or anyone else. He really likes me but wants to take it steady. What's the difference then I'm thinking? I wouldn't introduce him to the children until much further down the line. I'm 39 so really not been on the dating scene for many years so it's all fairly new to me x

When I asked about controlling he said ex girlfriends had changed and started telling him not to go out with his friends and how to spend his money

Doesn't sound likely, sounds like he has made up a load of bullsh1t to tell you not to expect anything from him.