What is causing my hair loss over the last year? (Photos)

Judging by the pictures provided, the best advice I can give you is to do your research and seek a reputable and experienced hair restoration surgeon for a thorough in-person evaluation. With that said, I don't believe you should chalk this up to just being related to stress because a few blood tests came back normal. Important factors to be considered: 
Family HistoryExam of the scalp and hairRunning appropriate blood testsPossible small scalp biopsyIn your specific case, we would want to rule out any underlying conditions first before diagnosing and treating you with male-pattern baldness. 
I've added a link to some possible and common medical conditions related to certain patterns of hair loss for insight. Hope this helps.

you need a formal evaluation for your hair loss. PRP/stem cells injections give the most improvement along with topicals and pills in certain cases if this is genetic .  Best, Dr. Emer.

Thank you for the question. I strongly advise that you see a hair loss specialist so that the proper labs can be checked and, if possible, a biopsy can be performed to help determine the cause.

This seem to be a retrograde alopecia case for which you need to undergo a formal hair evaluation by a surgeon. This is not a very well-known hair loss reason but is found to be very common among population these days. It is estimated that approximately two out of three hair loss sufferers experience some degree of retrograde alopecia in addition to their male patterned hair loss problems.

that is a retrograde alopecia case . I recommend you to have a dermatoscopic exam and ıf needed a skin biopsy and to have a full exam with an hair surgeon and/or endocrinologist , to find out any reason for hair loss.

From the photos it looks like there is receding at the hairline;  but several dermatologists should have been able to diagnose and treat male pattern hair loss.  The excess body hair suggests that you should be evaluated by an endocrinologist .  None of the blood tests you mentioned checked your hormone levels.

Retrograde alopecia vs alopecia areata are certainly two important considerations. What’s needed is an up close examination (with dermoscopy), review of blood tests and review of the whole story. If there is any doubt still... the next step is a punch biopsy.

In order to find out if your hair loss is a concern, you should see a professional.
The
number one first step I recommend is a comprehensive consultation with a
hair regrowth specialist who will perform lab tests to determine the
underlying cause of your thinning.  Without labs, no-one can really know
what your true cause is and any treatment will be temporary at best.
From here, you can receive the best treatment for your case.
Good luck on your search.

Hairless surgeons with a lot of experience in the field, tend to be very good at diagnosing the causes of hair loss. With that said, after reporting for interviews with dermatologist, I cannot make any judgment on you without a personal examination at the minimum.

In order to find the cause for your hair loss and recommend the proper treatment options, it is best to be examined by a hair loss specialist from close up and have the propwr tests done.