I thinks he is using different words to say mushkil pe mushkil aa jaai… we don’t say mushkil sey pehlay mushkil aa jai. If you look at the whole shair, the first misra has sitam-balaai-sitam which again has the same meaning namely sitam pe sitam.
Aik mushkil ke baad doosri mushkil makes sense rather than mushkil se pehlay mushkil. The second mushkil will be after the first one anyway.