Since I don’t know your account email, I can’t know if you ‘changed’ password or ‘reset’ password. However, regardless, the file will *always* open with the password that was in effect when it was originally encrypted.
So, if you can sign in to AxCrypt, and can’t open the file you should be presented with a file password dialog. The password to enter here is the one that was in effect on the day that you last encrypted the file.
Once you’re signed in to AxCrypt, you can try the file password for as many times you want. Signing in to AxCrypt (online) does limit the number of tries to 15, then you have to wait for an hour.
If you wish further clarification, please add some screen shots of where you’re stuck – this usually helps to clarify things for us a lot!