I've spent years davening incessantly for a shidduch, and recently I've tried to be more consistent about being kovea ittim, but unfortunately none of it seems to have any impact at all. Are there sources that talk about how you can "motivate" (so to speak) Hashem to listen to your tefillos?
Quoting from Adai Ad
Tefillah is not that we are trying to change Hashem’s mind about our lives. It is more about changing ourselves. When we change ourselves, our lives change.
This idea is well-known and accepted. Please read more on the site.
I agree with @N.T. I suggest you first daven that Hashem should open your heart to accept the idea of having a Rav with whom you can discuss your life. Then daven that you should locate this Rav. From then on it should be relatively easier.