Hey, I would suggest the following.
First check if cloud storage (icloud/google play/amazon cloud/etc...) is turned on, and if not, try connecting. If your main account was saved, it will ask if you want to continue, and will load your progress.
If that doesnt work then i can suggest the same as in my previous post: contact the in-game support (from your new account) and try to give any information you can remember about your account. Hopefully they will be able to locate your abandoned account and help restore it!
I'm also in a serious issue right now. I had installed King of Thieves a while ago, but then uninstalled it. A few days ago, I installed it again and started from scratch. I know my nickname, but I don't know my full player ID. I reached about level 10, I had bought the Royal Chest, bought 250+50 orbs and had two gems which totaled to around 100,000 rating. I was a part of a guild, but I forgot its name for some reason. I'm so nervous right now, I don't want to lose either my progress or my money. Please help.