Be encouraged and be mindful that only what you do for God will last. He is a rewarder to those who diligently seek Him and are handling Kingdom Business. Individuals may not appreciate you and all the hard work that you do but God sees and knows all.
"Therefore, my beloved brethren, be ye stedfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labour is not in vain in the Lord." ~1 Corinthians 15:58