Performance Review at Work

Hi!

I have a performance review at work this Thursday, which is well overdue.

I work in marketing, have been at this agency for over 2 years, have been with the business through a lot of good and bad times, and have got a lot of promotions over a small period of time. 

I get on with everyone on the team, especially my boss, who has been very understanding with my struggles with being autistic, and also recognises what my strengths are, which has been great. 

It's full time, 40hrs a week, plus a couple hours across the weekend when required, which is shared amongst us all on a rota.

It's no secret that I am vastly underpaid for what I do, as I now take on more responsibilities than what my role originally was - they even gave my role a unique title just for me, so essentially they couldn't really hire anyone else to replace all my tasks. 

They know that I am underpaid and it's been brought up a few times on the basis of waiting for new business and then take a look at it. 

On Thursday, I'm going to bring up my salary again, as now I'm recently married and looking to buy a house, which is something I can't do on this current pay. 

Do you have any any advice/guidance on how I should word this to my boss? 

What exactly should I say/how should I say it?

Thanks in advance!