MyEtherWallet.com (MEW) is just an interface to interact with the Ethereum protocol. When you create a new Ethereum wallet, MEW asks you for a password and then prompts you to save your "UTC / Json" file. This file contains your private key, but the key is encrypted with your password. If you have this file and the password, you can recover all the funds in your wallet with 100% certainty.
If you have this file and you have one or more guesses as to what your password might be, then you can attempt to brute force decrypt your password.
So, you need to do three things:
1. You need to search your computer for your Json file. If you find it, move on to step #2.
2. You need to develop a list of the passwords you might have used.
3. You need to test variations of those passwords against the Json file.
This article (
https://cryptoassetrecovery.com/2018/02/09/how-to-recover-your-lost-myetherwallet-mew-password/) will walk you through each of those three items, step-by-step, including screenshots from MEW and a systematic method for identifying potential password guesses.
Thanks,
Chris