In 2 Corinthians the Apostle Paul addresses a situation common to most of us at one time or another--a lack of appreciation of our efforts. It may be that no one seems to notice all that you do for the Lord. Or even worse, after all you have done for "the church" a person or group of people oppose you, cricize you, etc.
When you feel like you are in this situation first realize that you're not alone. Our Lord was rejected by the very multitudes that He had healed, taught, and fed. Paul was constantly followed and persecuted by not only the Jews but also judaizing teachers, who both tried to turn Paul's converts away from Paul (and Jesus). Apparently in Corinth they met with some success. Remember Jesus warned the apostles specifically (and you and I as well) that the world would hate them. Worldly brethren will reject you if you are not worldly. Some will reject you because of envy or jealousy--Phil. 1 records Paul's mention of some who preach out of envy.
Or you may be like Elijah, who thought he was the only one left in Israel when it was not the case. 7000 had not bowed their knees to Baal. Sometimes the perception that nobody cares is just that--a perception, but not the truth. Although you may not know it others are probably working for the Lord as well.
But with all that said does what men think of you really matter? We are not working for men but rather for God and God takes notice of all that we do. Does no one seem to appreciate your efforts? God does! And that's what it's all about, isn't it?