Is what I did—feeding 60 destitute people and fasting that day—sufficient to atone for the emission that occurred after the dawnathan in Ramadan, knowing that I am able to fast but feared embarrassment from being asked about the reason for my fasting?

If you engaged in foreplay before dawn, then dawn broke and you stopped the foreplay, and semen was discharged afterwards, then there is nothing upon you, your fast is valid, and you are not required to make up the day or offer expiation.

However, if the foreplay continued after the true dawn, leading to the discharge of semen, then you have erred and you must repent and make up the day, by agreement of the jurists, because your fast has become invalid. Expiation is not required, according to the preponderant opinion, except for breaking the fast by sexual intercourse.

And whoever owes a right to Allah must fulfill it and not abandon it out of shyness from people. Expiation is in order: freeing a slave, and if one cannot find one, then fasting for two consecutive months, and if one cannot find that, then feeding sixty needy persons.