If i fail on this diet to gain weight i am unsure what to try next.  Any
suggestions?

Good health,
mark

My suggestion would be to lift weights. You WILL gain some muscle, which is
the only weight you probably want to gain.( Unless you are trying to make
your mother stop staying, "Mark, you look so drawn" ( Which is what my
mother said whenever I manged to get down to a weight that I wanted)

Cheers, Michael