I’ve been a massive idiot – please help!

I never used to be good with money and saved up no where near the amount my girlfriend did last year when we were looking for a house together. I lied to her and she almost broke up with me when she found out, as it meant we couldn't afford a great deal for a house (which we live in now). Luckily she didn't break up with me and we negotiated a deal with a higher mortgage and I vowed to get better at dealing with finances. We are now engaged to be married and all has been great until May. My car had loads wrong with it and I told my fiance I had enough to pay for it but I didn't (the only reason I lied was because I had bought the engagement ring which was the reason for not having enough). I had to go into my overdraft and its just gotten worse as we are paying for a wedding and mortgage. I have now gone over my mortgage limit and need help desperately. It's gone on so long that I can't tell my fiance I have lied to her again. I am pulling my hair out every day and have never felt this low. I don't want a fortune and I don't want someone to make me rich, I just need help to get out of this hole and I have learned my lesson. I will never let this happen again. Any help will be incredibly appreciated. Thank you for reading this.