It sounds like you're saying that moderate meditation is overrated, and more intense meditation is outright detrimental in the long term. That is surprising to me. Is this an inevitability? Did you experience this, and how did you push through it?
And of course, there is probably something behind that too, of which I have no idea.
Apologies for chiming in, but the simple answer is that "you" can't. That is, if you believe that there is a "you" that can push past this barrier, then you will fail. It's an impossible task. Where you go after that realization is up to "you." ;)
Short therm meditation experiences are mostly overrated. I think even little a day regularly 20-30 minutes has good effects if you make it a habit that you don't give up.