Honestly - I really don't know what's up with you and BlossomRainFall, and truthfully I don't care.
I just hate seeing people accusing each other, calling each other names, cussing out each - pretty much anything rude.
So I'm just going to set straight what I know so maybe ya'll can get past this:
BlossomRainFall is also known as "CherryRainBlossom" on her weasyl and wattpad accounts. She had stated, right before you created your account, how she wished she could change her dA name to "CherryRainBlossom" so it matched up with her other accounts.
It could be a coincidence, it's strange, it could be that you DID steal the username, but I don't care.
As I said before - I just want ya'll to try to work it out without cussing, or calling each other names, or one trying to put the other down.
I hope you'll listen to what I had to say on the matter, and please don't take any of this the wrong way.
Also; welcome to deviantART. I hope your future here won't be as confusing or rude as it is now. ^w^