Private Key Problem: My New Steemit Account Doesn't Work

After receiving my Steemit account email, I logged into my very first account from my phone: @sunstone. Steemit gave me a 52 character password and told me to save it. I saved it, all 52 characters, carefully. Everything worked! A few days went by and I decided to use my account again. I tried to log in from my computer. The 52 character password (beginning with "P") didn't work. I opened up my phone and surprisingly, it was still logged into Steemit. I searched the forums for an answer to my issue, and posted a question. I took a screenshot of the page in my wallet that gives my different passwords. Then I clicked on one of the Private Key buttons to show it. It asked me for my password. I entered my password, and I guess it was incorrect and it logged me out. Now I'm logged out of my phone and I can't access @sunstone anymore. I know that some of you will say, are you sure you copied your whole password correctly? I'm sure of it. Without a doubt. I was very very careful. I cut & pasted it... it's 52 characters long, and I double-checked it after pasting. Also, it doesn't appear that my account was compromised because no one has posted with it except the one time that I did, and when I try to do the account password recovery, it says that no one has ever changed ownership. I have 2 questions:
1. Someone in the chat forum was kind enough to set up this new account for me. I'm grateful for the help because now I have a new Steemit account. When he created this new account, I received a 12-word seed. This allowed me to easily log into this new account @jeremyalan. The strange thing is, when I created my account through Steemit.com, I didn't receive a 12-word seed. Why is that? 2. Another person in the chat kindly offered to help me try to retrieve the 12-word seed from my 52-character Private Key for @sunstone. He admitted that it sounded sketchy because it would expose my Private Key to him... but he said, since my account was lost anyway, it wouldn't hurt anything. However, I want to liberate the 12-word seed so I can securely use @sunstone, so I'd rather not jeopardize the account just to see if I can solve the problem... Can anyone point me to an article on how to do this on my own? Any other insight is greatly appreciated!