Halsey “regrets” returning to music because she’s been viciously trolled by “mean” fans. The 29-year-old singer took time off after being struck down by autoimmune condition Lupus and a rare lymphoproliferative disorder, but made a comeback last month when she released new single ‘The End’ which was followed by ‘Lucky’ weeks later – but Halsey has confessed she regrets getting back to work because she’s been given such a tough time by her own fans. In a post on Tumblr, she explained: “My own fans are hands down meaner to me than any other people on the planet. Not speaking for all of you, of c…