My Galaxy name is different from online which actually shows the games. How do I get my right galaxy name and games back?
Now my Galaxy name is Tom_Doan62 and I didn't change a damn thing !..How do I change back to ttomm46 like it is online where it actually shows my games?

That's a new account, created this month, with 0 games.

1. In a web browser, go to your login and security settings and note the e-mail address you're using for the ttomm46 account.
2. In GOG Galaxy, click your avatar -- the middle icon in section in the top left -- and choose Sign Out.
3. After a few moments, the login box appears. Click the Change Account link at the bottom.
4. Log in with the e-mail address you made a note of earlier and the associated password.

If you somehow still get logged into the wrong account, I can only conclude something has gone very wrong server-side and only support can fix it.