How do I build up the courage to leave

[VarsVase]

DP of 5 years won’t commit. There’s no 2 ways about it. We have a nice life, see eachother 5/6 nights a week, go on holidays, have a big friendship group, he is my rock, gets on well with my family and DS, can’t do enough for me. But he won’t commit and I know this. But it’s so hard to just break it off. So hard

What do you want, marriage ?

Make a plan.

Plan to end it and then go no contact. It is easier to get over someone if you don’t see them. Delete and block him on everything.
Plan to stay off the booze if it’s likely to lead to you drunk texting.
Make a list of activities to fill your days. Recruit friends and family to help.

Make a poster and put it next to your mirror reminding yourself that you are worth more and that your needs are important.
Make a strong woman upbeat playlist.

Think about what else will help you.

Remind yourself that it will get easier

I think it tends more to come down to final straws

Yeah I want marriage and maybe another kid. I need to be stronger but it’s hard, we have so much planned.

Definitely yes to the final straw, I feel like one day something will happen and that’ll be it for me

Has he said absolutely no to a child ?
Personally I’d never get married again either.

I’m not 100% sure I want another child as mine is older now but I really want to get married. It’s just so hard

I think you need to lay it out for him in big letters, short words.

Marriage is important to you, and without it you don't feel valued, loved or secure. If he doesn't want marriage then you clearly want different things from life, and you need to accept that and leave.

If you are sure, set a date, ask him to help you move out. Calm and clear, dignity intact. And then cease all contact.

Sounds like a great relationship - except that you want marriage. Normally I'd say LTB but what would you be giving up, lots. How old are you both?
If you hard set on marriage then you have to be honest and tell him and be prepared to stick to it and potentially be on your own but available to find someone who is prepared to commit.