What is the meaning of "Alai Samchah Chamasecha"?
Rashi: [Your anger] leaned on me.
Radak: "Samchah" refer to closeness. The same applies to "Samach Melech Bavel El Yerushalayim" (Yechezkel 24:2). Also Chazal use it for proximity - 'Erev Shabbos Samuch la'Chashechah' (Shabbos 34a).
Malbim: Your anger is on me also in the grave. It is as if he feels life afflictions even after burial.
What is the meaning of "v'Chol Mishbarecha Inisa Selah"?
Rashi: "Mishbarecha" are waves of the sea 1 . All the storms of Your anger afflicted me constantly.
Radak: You afflicted me with all Your waves. He uses the metaphor of waves, for he compared himself to the depth of the sea.
Radak: Because they break when the sea is agitated. The same applies to "v'Chol Mishbarecha v'Galecha Alai Avaru" (42:8).