Self-inquiry. Books. Meetings. Web videos. Non-duality blogs. You've probably used these resources for years, and feel that you have made progress in understanding your true nature.
I admit it's difficult to discuss self-realization in terms of "reaching" or making progress, since all of the teachings clearly tell us there is nothing to attain and no progress to be made. We already are what we are seeking. However, on the relative level, we've all had the feeling of making progress -- and most of us have also had the feeling that we are stuck on some kind of plateau, unable to access the higher understanding we wish to realize.
What is holding us back? We understand it mentally. We have allowed feelings to surface. What is the stumbling block?
In many cases, I think it comes down to this: We have not allowed ALL feelings to surface. There are some we simply don't want to face. The unwillingness to allow all feelings to be as they are will short-circuit your investigation.
At the outset, almost everyone who engages in non-dual investigation allows many feelings to be there -- and that includes feelings they would never have welcomed previously. But few people allow this process to go all the way. In other words, they reach a point where the feelings become very uncomfortable, and they resist sitting with those feelings.
In my experience, (and I have seen this with most others) in the early period of self-inquiry, many of the "standard" feelings start to arise. These are the kinds of feelings (and beliefs) you recognized even before you learned anything about non-duality. "I'm not good enough," "I'm not loveable," -- stuff like that. However, as the investigation continues, deeper and deeper layers of feelings come to the surface.
With many of these, there is no specific reference point or explanation for these feelings. You might feel scared, angry, depressed, jealous... and have no reason why such feelings are arising. You can't point to something in your childhood or adult life that explains it. These are raw emotions coming up, and they invite you to let them be welcome.
And that is when some people pull back. And that is often when the investigation stalls at what seems like a plateau.
There is nothing wrong with pulling back. You may not be ready to take those emotions full force right now. When you're ready, you will allow them. You won't know in advance how long the uncomfortable emotions will be there, or how strong they will be.
I'm not suggesting that everyone has to go through a "dark night of the soul" with crippling emotions and anguish. The severity of the emotions will vary in each case. Don't compare yourself to anyone else.
However, if you find yourself at a plateau and stalled in your inquiry, consider the fact that you may not be allowing all of the emotions to surface. You may be hoping that you can somehow bypass these feelings and come to self-realization without facing them.
I think that any self-realized teacher will advise you that there are no shortcuts or bypasses that work. Sooner or later, these feelings have to be faced. ALL of them.