I had this exact issue!
About a week or so after my diagnosis i was noticing much more hair loss then usual, and freaked out because i thought it may be a thyroid issue, so i had some blood work and my thyroid was fine. So...
Turns out that 'Hair loss from stress" is something that usually occurs a couple months AFTER the stress starts, its not like on TV when it happens the day you miss your flight or after a tough meeting at work lol
Hair follicles go through a cycle, and the last phase in the cycle is the 'resting' phase where they just rest for a month or so, and then fall out. When your body goes through significant stress (like undiagnosed diabetes can put you through) many more follicles enter into that rest phase, and that phase becomes a bit shorter so your body doesn't have to deal with resting hair lol. So this means that more of your hair will end up fall out a month or so later, depending on the amount and duration of stress your body was under..
This will last for like 2-3 months, but then it should return to its normal cycle.. So everything should work itself out, well mine did, its better then ever now lol
Best of luck!