Five months ago I created a bitcoin wallet in electrum. I created the seed phrase in electrum (I'm 90% sure) on a macbook.
Why 90% sure?
It is very dangerous if you do something and are pretty sure 90% about for instance you created a Bitcoin wallet with Electrum software while 10% is not with Electrum.
I put a small amount there, deleted the wallet file, deleted electrum. I immediately reinstalled electrum, entered the seed phrase, the wallet was restored, the amount was displayed on the balance. The seed phrase is absolutely correct, I rewrote it many times and remembered it, entered it exactly from a piece of paper. The seed phrase was 12 words without an additional word. I transferred a larger sum there.
After that, I deleted the wallet file. Then restored it. Then deleted it again.
You need to create your wallet, backup, test backup for recovery. It's risky if you fund your wallet, did not test backup and recovery before deleting your wallet.
If you already backed up a wallet, tested a wallet backup for recovery, and all worked well, I am too skeptical that why later you failed to recover your wallet from backup.
5 months later I am trying to restore it, the balance is 0. I found the address in the blockchain where I transferred the money, btc is there, but this address is not in the list of wallet addresses. I tried to restore the wallet in BlueWallet, it identified the seed phrase as electrum segwit. 0 ballance.
Any ideas what to do now?
Try to restore your Electrum wallet with three address types: Native Segwit, Nested Segwit and Legacy and see the wallet balance.
Generally
How to back up a seed phrase is a helpful guide.
With Electrum.
https://coinguides.org/electrum-seed-restoring-wallet-finding-seed/Click on Options, and you can type
p2pkh for Legacy address
p2wpkh-p2sh for Nested Segwit address
p2wpkh for Native Segwit address.
Making sure you know what is your address type on blockchain explorer (you already checked the address balance with it).