Did Paul experience constant satanic attack?
Yes. Paul was under constant satanic attack. After being forced from Ephesus by pagan hatred of the gospel, he went to Troas, where he expected Titus, yet this opposition was not new; Satan has opposed God's redemptive plan since Genesis 3:15.
Les explains that Paul’s second letter was written after he had been forced out of Ephesus because of the tremendous hatred for the gospel from the pagan followers of Diana, whose statue oversaw the city. After leaving Ephesus, Paul went north into the northwest corner of what is now Turkey to the ancient city of Troas, which was Troy. There he evidently began a little congregation. He was supposed to meet Titus, and Les initially hesitates between Titus and Timothy but concludes it was Titus, pointing to chapter 2, verse 13. Les says he gives this background to show why this man was under such constant satanic attack. He adds that this is nothing new: as soon as God made the classic statement in Genesis 3:15 that the seed of the woman would bruise the head of the serpent, Satan knew it meant the coming of a Redeemer, so Satan kicked in gear everything to prohibit the coming of a Redeemer for the human race.