Hi Zenhen,
I’m sorry to hear about your depression. I’ve suffered a number of bouts of depression and anxiety and I can empathize with the challenges they present.

I have found that a couple of Buddhist practices do help me.
1) lovingkindness or Metta meditation. Repeating the caring lines of this meditation reminds me to treat myself kindly and helps me to feel loved. Sharing this with “all beings” (even if I don’t feel it) helps to reform connection to others, which I think is important because depression can be so isolating.

2) Mindfulness helps me to note my thoughts and it can be a bit surprising just how repetitive and nasty they can be. I actually note the thoughts very actively by thinking “I’m having the thought that nothing is worthwhile” or whatever. This seems to help me separate myself from the thought. The thought is not me. It is a thought, and this helps me to see that the depression is an experience of the mind and body. I can see it as something that is happening now due to a chemical imbalance in the body, but it won’t go on for ever.

I usually accept that I am going to find the experience of depression as “unpleasant” and I think I am a long way from successfully moving it to “neutral” status, but showing self-compassion and mindfully observing the experience has helped me. A book I’ve really found helpful is “The Happiness Trap” by Russ Harris. It is not a Buddhist book as such, but a guide to using mindfulness to help with mental health.

Good luck!

PS I’ve sort of assumed you are familiar with loving kindness practice. If not, check out Sharon Salzberg on google.