First advice: don't clear your browser cookies.
2nd advice: maybe try to do a password recovery through the Stolen Accounts Recovery (sandwich menu top right on any steemit.com page). Be sure to try that in another browser not the one you're using to post on steemit as that might log you out. ALso, this would work if you ever changed your password.
3 Not sure how you signed up, but maybe there can be a way Steemit Inc . can implement to recover passwords via the phone number provided? Not sure about this.

PS> If Hive account@jmc is the account in discussion here, I understand you are upset about losing immediate access to your steem, but looking at your account, it's only about 140 steem which is quite low in terms of value. I can send you 50 steem if you create another account to sort this out short term.