I realize that you said that you searched the web for an answer, but, to be honest, this is a much more common problem than one might think. I don't know how you have been searching for an answer, but try this:
Google {font installed but not showing in photoshop}, and you will see ~650,000 hits, many of which appear to be relevant -- just not specific to the particular font that is giving you problems.
There reasons for such font problems can be broken down into several common types:
a) This particular font is corrupt. (There are ways to check all your fonts for such problems.)
b) The font actually is present in PS's list, but is listed in a place that you didn't expect, eg, among Asian fonts or some other group, or the name listed in PS begins with some unexpected characters.
c) Only one face of the font seems to be present, but the others (eg, bold, italic, heavy, etc.) can only be seen by accessing them through the appropriate menu.
etc.
etc.
So, have you already eliminated (a), (b) and (c), above? If so, the next place to go to systematically troubleshoot your problem is this note from Adobe:
https://helpx.adobe.com/photoshop/kb/troubleshoot-fonts-photoshop-cs5.html
If that doesn't work, make the font file available to us and one of us will check it. You can either post it on some Dropbox-clone for which the recipient doesn't need to register to download a file (e.g., WeTransfer.com ) or just zip it and post the zipped file directly to this forum the same way you would post an image file -- just ignore the warnings.
HTH,
Tom M
PS - If you get the font to show up as it should, please let us know what worked -- we all learn from that.