I don’t have the capacity mentally to give 100 percent into a relationship so I know that’s on my part
Do you think that you have to be ok with being together all the time in order to give 100% in a relationship? Can you reframe this as 'I can only give 100% into a relationship if I maintain my own needs and boundaries'?
If it's necessary for you to only see your partner two evenings a week in order to be at your best in the relationship, then you need a partner who is happy to live in this way. Otherwise you're not compatible.
it’s a cry out for some time on my own
You're dramatising. Communicating that you need some alone time isn't a 'cry out', it's a simple 'I'm going to have a couple of nights on my own this week, sweetheart.'
Can you see that you're making your basic needs into something dramatic? If you need him to clean up, say 'Can you clean this up before you go, love? I can't be picking up after you as well as the kids.' If he books something, say to him 'I can't afford a hotel until 5 weeks after that, can you check with me next time, please, rather than just expecting me to have the money ready?'
What stops you saying what you need and want? What turns it into 'OMG I'm going to have to tell him I don't like his behaviour, it's awful/terrible/etc'? Do you know where that behaviour pattern comes from?
It's worth getting this worked out because if you can't calmly state what you want and need, you won't get it, in this or any other relationship.