So you have Electrum wallet with only one private key which you import from blockchain.com wallet, which means you do not have seed words, is that correct? But since you use that wallet for one year you made some transaction or not?

Something is obviously wrong with that specific wallet, and since you can not fix it in any usual way, only thing which would be advisable to do now is clean installation of Electrum. But for that you need to have seed or backup of every private key from your wallet for make full recovery of your funds.

You can see private key of any address from your wallet by click on Address tab - then right click on address - you get private key - copy/paste. Then you can use option New/Restore - and create new wallet by importing one or more private key.

More info : http://docs.electrum.org/en/latest/faq.html