This topic in your post is something I can understand and relate to very easily. Having just spent four years waiting for my diability case to be settled, while living on less then one-hundred dollars a month.
There is no way I am going to tell you that having loads of money buys happiness. However, lack of enough money is not the answer either, but I will add a few suggestions. Instead of going out, if possible invite some friends over who can help with food & drink, and include your girl. Watch a movie or sports game.
There usually are many churches that have some kind of choir singing events this time of year. Most are free or for a small donation. Also if your into art or musems, that is a different sort of date, but it is an interesting one that can be fun. They are not so crowded this time of year.
Another idea is to walk or drive around looking at all the Christmas lights and do window shopping. Then stop in somewhere for coffee or cocoa to warm up.
These are things I have done when money was tight.