Many of the people missionaries work with are suffering compared to Western standards, and all their needs simply cannot be met. Since missionaries are out of their home country and do not have large financial resources, they may feel guilty about not caring for aging parents. People in their own cultures often have problems dealing with their affluence, the suffering of others, their children's education, their aging parents, and their government, so the difference is one of degree, not of kind. The natural response to realizing you are guilty is to try to hide or rationalize, such as Adam and Eve did. However, that will not solve the problem.
Missionaries are familiar with what to do about sin, but here is a review of the steps.
Certainly confess your sins to God. You may also want to confess to people you have harmed as well. Confession usually should be only to those actually affected by the sin rather than to the general public. We are to turn from our sinful ways to God. After forgiving her, Jesus told the woman taken in adultery to sin no more.