Hello.
I have been trying to recover my wallet with about 180BTC almost for one year.
I was ”clever” enough to create a wallet with SHA256 custom string entry, and didn’t bother saving neither SHA256 result of it nor the private key WIF. I had it for years on my computer. But the computer crashed and I am now unable to remember what the string entry was. However, I know what keys I used but cannot remember the pattern.
Can you elaborate a little bit more on how you created your wallet? I (and maybe others) don't get all the pieces together.
You had a custom string from which you derived its SHA256. This resulting 32 Byte SHA256 hash string could serve as a seed for a HD wallet or as a raw private key which you could've converted to WIF format for a single address paperwallet. The former would create a whole wallet with possibly lots of used addresses, the later just one paperwallet holding all your ~180BTC.
Having no documentation of your "clever procedure" backfires on you, apparently. I mention this solely as a warning to other users that this is a recipe for coin desaster as storage for wallets can always fail. And sorry to add: no backups, no mercy (again, to emphasize the importance for backups, especially for such wealth, and for anything stored on a device that is more worth than the device and it's backup combined).
If you had a wallet on your failed drive: was the wallet sufficiently password protected? Strong enough password? Do you remember that password with confidence?
If it was good enough password protected you could ask for professional data recovery from your failed device (there are a few well known companies for such tasks). You can ask for a quote and it may cost you some decent amount of money, but might be a more promissing path for recovery, depending on your current recovery puzzle.
If your wallet wasn't properly password protected then a professional data recovery might be a potential risk for your Bitcoins.
What exactly have you done in the past year of your recovery trial? Just curious to get a glimpse of what puzzle pieces you obtained in that time.
The suggestions to look for your address(es) in some address dumps assume that your 180BTC are on a single address which I doubt if you had a full wallet. If you had a paperwallet, then it shouldn't be too hard to find some address candidates.
I am asking for more details because usually people can provide more focused help if the puzzle is laid out more accurately.