Continue developing yourself, but stop watching pickup videos/seminars.

That stuff is 10/10 great for when you're building a rotation of girls and creating a situation of sexual choice, but is absolute poison to your relationship. It will make you constantly paranoid that you're missing out on something and that you're only one mistake away from your girlfriend cheating on you.

Once you're in the relationship, go back to books such as The Power of Now, the 5 Love Languages, and The Way of the Superior Man. Become more centered while simultaneously more emotionally vulnerable and connected with your woman.

I also noticed that cutting out hip-hop and rap music who's mantra is "fuck bitches get money" also helps to ease paranoia and helps you to stay more down to earth with your chick.

Pretty much you need to ease your way out of pimp mode and ease your way into high-value, masculine badass mode.

TL;DR: Examine the influences that are going into your brain at different stages in the relationship. They can have a very real impact on your view of reality.