It says in Torah 89 in Likutei Moharan that when a person sees lack and problems in the world, naturally you become depressed. The truth is that all problems in the world or in a person themselves are only a reflection of lack in the Shechinah. In order to remedy depression and stress that come from this observation is to realize that Hashem has given a great kovod, a great honor, to you that you should be able to notice these things.
In the next Torah, Rebbe Nachman teaches that all problems come upon a person due to the Shviras HaKeilim, the Breaking of the Vessels that happened after Hashem created the world. The way to repair this is to rejoice in Hashem our God, and through this all the lacks will be fixed and brought to completion.
From this, we can learn a practical aspect to avodas Hashem. In our woefully degraded generation your average person is not on the madreigah (level) to rejoice in Hashem and the Shechinah simply through thought. It says in the posuk “ישמח השם בכל מעשיו”, Hashem rejoices in all His Creations. The last word could be translated as “Actions,” rather than “Creations.” The Tanya states that every Yid has a Chelek Elokah MiMa’al Mamesh, a chunk of God from on High, within their Nefesh Elokis, their Godly Soul. When you genuinely try to live with Hashem as an actual part of you, and every action is directly tied up with this knowledge that Hashem is part of you as you are part of Him, then through engagement with the physical world in a joyful manner can you accomplish the Tikkunim (reparations) that need to be done to the Shechinah. Even though we recognize there are personal problems as well as problems in the world at large, meaning problems even within the Shechina, r’l, we must know that we can fix these through engaging with Gashmiyus (physicality) with joy. The best way is to state before engaging with any given activity, especially one bringing pleasure and joy “לשם יחוד קודשא בריך הוא ושכינתיה”, in translation, “For the sake of the unification of the Holy One Blessed be He and His Shechinah.”