This doesn’t sound like boredom to me. Boredom is usually a response to a lack of stimulation and the inability to do anything about it. A person who is bored has plenty of energy but can’t find an interesting or satisfying activity.
What you describe is more in line with your diagnosis of depression. A classic symptom of depression is feeling helpless and hopeless to deal with one’s dark feelings. People who are clinically depressed often feel “empty” or numb. It’s possible that you have labeled these feelings as “boredom”. It’s more likely that you are experiencing a depression that has been present most of your life.
You say that you have had depression and anxiety for many years. I hope those diagnoses are the result of a professional assessment, not a search of the internet. You need and deserve a thorough assessment and treatment by a qualified mental health professional. You don’t have to struggle with this alone. You don’t have to live this way for the rest of your life.
Chances are, you will be asked to start with a thorough physical examination. There are a number of medical conditions that cause or contribute to feelings like you describe. If your physician finds nothing wrong, then it’s time to seek out or return to a psychiatrist and a counselor. You might benefit from taking an antidepressant. I always urge people to also see a talk therapist. Medication alone is seldom enough to change a person’s point of view about themselves when they have been struggling as long as you have.
I hope you will take this advice seriously and follow up. You deserve to have a better life.
I wish you well.