No matter how many times I try to repress unpleasant thoughts, they reappear.
The unpleasant thoughts come up despite my repeated efforts to repress them.
ご質問ありがとうございます。
① "No matter how many times I try to repress the unpleasant thoughts"＝「何度も不快な思いを抑制しようと私がしても」
"they reappear."＝「それは（不快な思いは）また現れる。」
② "The unpleasant thoughts come up"＝「不快な考えは現れる」
"despite my repeated efforts to repress them."＝「それらを抑制しようとする私の努力にもかかわらず。」
ご参考に。
アメリカ合衆国 
