I've been lying to my girlfriend about having a savings account for over a year

When my girlfriend and I got serious about a year and a half ago we had the money talk. She asked if I had savings and I said yeah I've got like $8k saved up. I didn't. I had maybe $600 in my checking account and that was it. I don't even know why I lied. I think I just felt embarrassed that I'm 27 and have no savings at all. She's really responsible with money and I didn't want her to think I was a mess. Now it's been over a year and she still thinks I have this savings account. She'll mention it sometimes like "at least you have your emergency fund if something happens" and I just agree with her. We've been talking about moving in together and she wants to combine our savings for the security deposit. That's when this is all gonna blow up because obviously I don't have $8k to contribute. I finally started actually saving money a few months ago. Been using an app to track everything and I've got like $2,400 now which is the most I've ever had. But that's nowhere near the $8k she thinks I have. I know I need to tell her but I have no idea how. "Hey remember that savings I mentioned? Yeah that was a lie and I've been lying about it for a year and a half." She's gonna be so mad. Not even about the money, just about the lying. And she should be. It's a stupid lie that I just kept going with because I didn't know how to fix it. I'm planning to tell her this weekend. Probably gonna ruin the relationship but I can't keep doing this. The longer I wait the worse it gets. Just needed to say this somewhere before I actually have to say it to her. I'm an idiot.