This is a serious post if you can help me I am willing to give you 50%
Give the recovery task to Dave of
https://www.walletrecoveryservices.com/contact/. He's an expert, doesn't scam people and will guide you through the process. Dave will also only charge you 20% and only when he succeeds, zero otherwise. When your wallet is worth more than $100k his charge could even drop to 15% if wallet's password isn't exceptionally complex.
Dave also doesn't need your full wallet.dat file (only a portion of it), anyone who asks for the whole wallet.dat, is very very likely a scammer. Be careful!!!
Dave will guide you to extract some little data of the encrypted wallet passphrase from your wallet.dat file, that's all he needs. If you give initialy more than that or your full wallet.dat to someone else who claims he can help, you can kiss your coins goodbye.
I have no affiliation with Dave's reputed business, I just cite from his cite. His account
walletrecoveryservices seems inactive. This is his announcement of his services in this forum:
Bitcoin Wallet Recovery ServicesHere's a quote from a Bitcoin Core dev and reputable forum's staff member about Dave's service:
There are many programs that can brute force things, and when run on a distributed system or a cluster, they can brute force passwords very quickly. Given wordlists of potential password candidates and word mangling rules, it can be relatively easy to brute force a password.
I have actually known about wallet recovery services, and you don't need to send them the full wallet, just parts of it which can be dumped using pywallet. They require the part regarding the password and 1 or 2 addresses from the wallet that can be empty. This safeguards your coins if they should try to steal them. The info about this is here:
http://www.walletrecoveryservices.com/information.htmlAGAIN, OP, you will be contacted by a lot of people, all pretending to be able to recover your coins. They might be able, but most of them might scam you. You can't know whom you can trust. Talk with Dave, that's likely your best chance. To recover the wallet's password it would help immensely if you can remember how you usually constructed your passwords. People are mostly lazy with their passwords and stick to their known routine or have a bunch of re-used passwords.
P.S.
To my knowledge in those early years of Bitcoin there weren't many options for exchanges or other wallets. So I'm assuming OP has an old legacy BitcoinGUI wallet.dat file. Don't quite remember when BitcoinGUI (today Bitcoin Core) introduced wallet.dat encryption passphrases... (very early wallets didn't have any encryption of the wallet file at all).