allmusic lists 109 recordings called I CAN'T HELP MYSELF, but it seems there are several songs with the same title. There are still more with similar titles (CAN'T HELP MYSELF, JUST CAN'T HELP MYSELF, I JUST CAN'T HELP MYSELF, etc.). The one recorded by The Gems was written by Leonard Caston and Billy Davis. It includes these lyrics, which I transcribed from a sound sample:

...when in my heart I know you belong to someone else.
Oh, my darling, I just can't help myself. (I just can't help myself.)
(Why?) Why do I hurt inside?
(Why?) Why do you make me forget my [pride?]...

The song doesn't sound familiar to me. Are you sure this is the one you want?

The one in this group most familiar to me is I CAN'T HELP MYSELF (SUGAR PIE, HONEY BUNCH) written by Lamont Dozier, Brian Holland, and Eddie Holland, which was a big hit for The Four Tops in 1965.