I bought Adobe Helvetica fonts sometime ago. I do not know where it went.
It does not show up in MS word.
Please help me to download this font
Adobe has no place where one can simply download such previously licensed fonts from.
Assuming that you have documentation of your font license acquisition from Adobe, you might try contacting Adobe Customer Support by phone and seeing if there is any way that a copy of the font file(s) can be obtained for you.
Note that the best bet for you is to review your system backups and retrieve the font files from same.