A wall of energy slammed me back during meditation? What was this? 2 years ago, I was meditating for about 2 hours a day and was rapidly transitioning to a higher vibration when all of the sudden, I was slammed back by a force of energy back into my chair. Since then I havent been able to get as deep into meditation as I did before then. Im not sure what happened, but feel some kind of a block happened. Has anyone else experienced this or know what happened?
If your breathing, body &amp; mind are currently functioning normally, I would forget about it because your question is an example of 'attachment', which Buddhism teaches to let go of. 

Naturally, I can't say exactly what happened, whether the cause was purely mental (a cathartic emotion); or otherwise purely energetic due to some kind of (non-Buddhist) yogic energy manipulation? But obviously what you regarded as "deep" was merely something unnaturally forced &amp; temporary. It sounds like you pushed to some kind of limit in your energetic-breathing-nervous-system due to non-Buddhist yogic practice. 

You should ensure your breathing is currently normal because excessive yogic practises can bring harm to the body, breathing &amp; nervous system. 

Buddhist meditation has its foundation in letting-go &amp; non-attachment rather than pushing or manipulating. 

Below is an example of a yoga practice called 'pranayama', which is a deliberate controlling of breathing: