You gave me a little happiness during a tough time in my life.
Everyday was so busy and tough for me, but your piano lesson gave me a little joy in my life.
この場合、次のような言い方ができますよ。
ーYou gave me a little happiness during a tough time in my life.
「私の人生の大変な時に、あなたは私に小さな幸せを与えてくれました」
ーEveryday was so busy and tough for me, but your piano lesson gave me a little joy in my life.
「毎日がとても忙しくて大変だったけど、あなたのピアノのレッスンは人生に小さな喜びを与えてくれました」
ご参考まで!