I see two possibilities, given you seem to want to go back on the Lexapro --
you can try it again after slowly tapering off the
Zoloft -- maybe the break in time off it will allow it to work again. Not likely to happen, but possible, depending on how long has passed. Or you could try Celexa, which is almost the same drug as Lexapro but enough different that it might help you the way the Lexapro did. No way to know, though, other than trial and error. Good luck.