Hi th1996,
Have you experienced depression before taking up spiritual practices? And do spiritual practices make it worse, or are practices a primary cause of depression? Sorry if you have covered all of this before in this topic (I am a bit behind), but it seems like you should be doing something different.
Your bhakti is very strong which is wonderful, but as you say, a steady practice you should not have to be constantly adjusting due to overload or depression is what you need. Are you familiar with Lesson 367 on measures for sensitivity to meditation with mantra? It may be that using breath as object would be more suitable for you, or even the passive awareness technique, as discussed in this recent topic on sensitivity to both mantra and breath meditation.
Also, if the depression has been occurring before spiritual practices or not primarily because of practices, have you sought medical assistance? If there is a chemical imbalance not related to spiritual practices, medical assistance could help.
May you find stability in your practice and life, so your spiritual longing can be fulfilled with good progress, comfort and safety.
The guru is in you.