Should we stay in this or move on?

I have been having problems with my girlfriend for a few months and don’t know if this relationship will survive much longer because neither of us is being able to navigate our issues. My girlfriend’s birthday is coming up, and I am torn between doing something extravagant for her or ignoring it completely. If I choose the former, maybe she will change her mind and look at this relationship differently. If I ignore it, she may finally decide that this has run its course, and we may be able to start the process of moving on. What is the best approach for us?
It may make sense to first figure out what you want before letting your decision drive any course of action. Birthdays aren’t about extravagant gestures if the importance of a person isn’t being acknowledged. The dilemma you have created for yourself also puts the onus of both possibilities on your girlfriend’s shoulders, absolving you from any responsibility. If you don’t want this relationship to work, tell her about it. If you don’t know where it is going, initiate a conversation about it. To rely on her birthday gift or lack of it to define what happens next doesn’t do anything for either of you because it fails to address any aspect of the real problem.

How do I know if someone is with me just because I pay for everything? I think I am not the kind of person she would normally go out with.
If your insecurity makes you question why someone is with you, the thing to ask yourself is why you deem yourself so unworthy. If you don’t believe this relationship is real, you are allowed to question it. This isn’t to say that it’s impossible for someone to date you for the wrong reasons, but why assume the worst without any basis? Time is usually the best way to figure things out. If this isn’t real, it will be hard for your partner to keep up the pretence for too long.