there was a wallet file corruption bug in previous versions. you may have been hit by that. i suggest starting over on a fresh PC. leave your current system untouched for reference purposes. restore from the private keys corresponding to addresses with unspent outputs (coins).
The problem is as mentioned above. I have only select private keys, the Addresses that Electrum made from who knows where,
i should have included a link to the relevant github issue. the wallet file corruption bug results in wallets displaying addresses from a different seed/wallet. it requires you to have generated more than one wallet in a session and for you to have a dodgy drive. for example USB drives are disproportionately effected.