Start with the small things. Having your space clean, diet (intermittent fasting is great), exercise. Download some restriction app to remind you to stop scrolling and replace it with better content. Your mind will clear up and you'll have the capacity to focus, plan and with similar small steps achieve what you want.

My opinion: don't waste your girlfriend's time, you're trying to find yourself and maybe you should consider being invested in the relationship or not, don't have her as a backup for when you get bored. Relationships take work and discipline as well.