This is a huge security risk. Using the same password for things like email, social media, forums, and exchanges is just asking to be hacked. There have been some pretty major password leaks from some very reputable companies over the past few years - it is highly likely that less reputable companies like small crypto exchanges will leak your password at some point. If an attacker was to gain access to one of your accounts, you could lose everything.

If you are struggling to use different passwords or remember them all, then just use a secure password manager like KeePass.