OP lost password and did not back up so the bruteforce is a way to go with.
Brute-force process will be easier if OP can remember some characters for that password. If the password is very long and OP don't remember any character, brute-force might take too much time.
I am curious as to how did you forget your blockchain password with that much amount of bitcoin in it, I want to know the story behind it because this could be a story that will help other newbies in what shouldn't be done to lose their password.
Such story mostly comes from old wallets when bitcoin was cheaper than now. A long time you don't log in one wallet, the bigger probability that you will forget its password. If you log in it every day or once in a few weeks, you might still remember the password.
https://www.youtube.com/watch?v=rMtW8vIHHekOP, do you have access to your email that was used to register your blockchain.info ~ blockchain.com (now) account?