I heard most of the miners are shutting down their gigs, Is it true? So, Is this the end of Bitcoin? 
There was an article about miners in China shutting down their rigs and this has nothing to do with cost of electricity or difficulty, but this is more on the equipment itself reaching the lifespan where it needs to be shut down or replaced or else maintenance of such equipment will be more expensive.Chinese miners are always going to be the last ones shutting anything down. even if their equipment is outdated they simply upgrade it since they have access to fast shipment of ASICs from Bitmain which is in the same country and easy to access.
besides ASICs don't expire all at the same time! there was new versions released which made it less profitable to run the old ones so some started shutting down or upgrading. that shouldn't cause much of a hashrate drop in my opinion.