Bipolar disorder, is often not recognized as an illness, and people may suffer for years before it is properly diagnosed and treated and it is more likely to affect the children of parents who have the illness.
You've mentioned that you keep your self busy to avoid negative thoughts.
Do you feel full of energy at that moment?
Do you have periods when you feel increased energy, activity, and restlessness?
Do you found yourself extremely irritable sometimes?
Are there days when you have provocative, intrusive, or aggressive behavior?
Probably, you doctor is thinking for you that you may have bipolar II disorder.
It's a form of bipolar disorder when people never develop severe mania but instead experience milder episodes of hypomania that alternate with depression.
Did your doctor mentioned the need to monitors your symptom for a week or two?