You say you try to slow down the mind enough so you can stay in the Self, but there is no need to ‘slow down the mind’ for this. The mind has never been able to stay in the Self by effort. This is all due to much misunderstanding. Please listen:
to stay in something is an effort. It requires a dedication and a skill.

It would require full time commitment, devotion, determination, single-mindedness. Even the Buddha could not do it. People have spent many years naked in caves trying to convert or merge the mind inside the heart, and have failed. They may have achieved something they did not have before, like peace or concentration or even joy, but they retain their identity as a seeker or practitioner—an entity who attains something. They may become a peaceful person, but there is a duality there. They must Be the peace itself. The Self cannot be reached or owned by anyone. It can only be discovered and recognised as the effortless and natural source of all which Is and appears.

How do you ask something as fickle as the mind to stay in something as absolute as the Self?

Isn’t it all a little ridiculous?