Bloodwork and Depression/Anxiety

I went in for a physical a while back. I’ve known for a while now that I’ve been stuck in depression and then added anxiety while going through divorce. I asked to have my blood levels checked. They only checked Thyroid and Hemoglobin even though I asked for a thorough check up. The tests came back low but barely within range on one. I finally had to go to a health store and pay to have my bloodwork done. That found alarming low levels of B12, B6, Vitamin D and extremely low testosterone of 125. Now I had to pay to give myself testosterone shots and another med to help start producing it again. I’m not sure it’s working. I should be able to do this through my insurance instead of out of pocket. I do now realize it was causing by depression and anxiety because it started going away as I took the vitamins and testosterone. Why don’t Drs look at these things first? So many people are suffering at my age of 54 and are being told it’s normal. Please start with those tests before giving out depression and anxiety meds. Sometimes that’s not the issue. I had brain fog. I was tired all the time. My man boobs were horrible. It is all slowly getting better but only because I initiated these tests. Please tell me why Drs don’t check these things more often. I’m guessing lack of training or awareness. I would love to hear from others dealing with similar issues.