I'm sorry you're having a hard time.

Bipolar is not easy to diagnose and I think doctors are careful about dismissing it.

It took years to get my diagnosis. I went from occasional panic attacks, to generalized anxiety disorder, to depression, and finally years later bipolar after seeing specialists.

You could be in the early stages and the doctors might feel you're not quite there yet in terms of your symptoms, but I don't know of course.

Like you my manic phases don't get to the extremes you might have read about but my depressions are really bad. I was diagnosed after anti depressants caused a manic episode that lasted a long time.

I think you should keep track of your moods, sleep, and weight and get a physical done to make sure you're healthy since lots of physical problems can cause what looks like mental health issues. Also avoid drugs and alcohol.

Once you have collected some data about how you have been doing, try going to the doctor again. The data will help him/her see if there's a pattern that needs further investigation.

I hope I have helped you. Let us know how things go.