No, gedit can only edit a text file. The text file “~/.profile” is a (hidden in your home folder, there is a dot in front of it) configuration file that gets read each time you log in. There you can export the path, so it will work for the whole installation, but only after you completely log out the user and log back in again. A simple export will only work in the terminal or script where you started it. VST_PATH is not a text file like “~/.profile”, but a system variable, there is a difference.
Is the output you get from a fresh termina, i.e. did you close the terminal and start a new onel? I see there are multiple copies of the path, and also “/path/to/my/vst” which is probably from some tutorial and an invalid path. Maybe that breaks the compatibility. What have you tried so far to set the VST_PATH? Maybe some "~/.bashrc?