How can I unbrick my Verizon Galaxy S3 SCH-I535?

[AC Question]

My aunt gave me her Verizon Samsung Galaxy S3 SCH-I535 a couple weeks ago. It was running Android 4.4.3 "kitkat" when I got it, but I wanted to upgrade it to Android 5.1 "lollipop". I found out that the Verizon phones have a locked bootloader, so I tried to get around it by using Safestrap. I THOUGHT I had backed up my system, but I can't find the files anywhere. WHen I tried to install Andoid 5.1.1, I got a bunch of mount errors, and now my phone sticks on the initial "Galaxy SIII" screen when I boot up, and my computer does not recognize the phone. Kies also does not recognize the phone. I CAN boot into Odin mode, and if I have Odin up and running Odin recognizes the phone, but when I try to load any edition of ANdroid I get a "FAILED" message from Odin. Is there any way I can restore my phone to at least where it was when I got it?