John Gill Commentary Psalms 88:4

"I am reckoned with them that go down into the pit; I am as a man that hath no help," — Psalms 88:4 (ASV)

I am counted with them that go down into the pit
With the dead, with them that are worthy of death, with malefactors that are judicially put to death, and are not laid in a common grave, but put into a pit together:

Thus Christ was reckoned and accounted of by the Jews; the sanhedrim counted him worthy of death; and the common people cried out Crucify him; and they did crucify him between two malefactors; and so he was numbered or counted with transgressors, and as one of them, (Isaiah 53:3Isaiah 53:4Isaiah 53:12) .

I am as a man that has no strength ;
for his "strength" was "dried up like a potsherd", (Psalms 22:15) , though he was the mighty God, and, as man, was made strong by the Lord for himself.