Hi,
I'm sorry for your loss; losing parents can take a long time to come to terms with :(
Medications and stress are a few of the top issues that can really mess up menstrual cycles, as I'm sure you're aware. Another reason that you're cycle might be changing and why you may be experiencing sore breasts, is your age ~ what you've described isn't uncommon for women to experience between their 30's & 40's. For more info. you might want to research 'perimenopause'. Also you may want to start tracking your cycles, and definitely speak with your doctor if the symptoms continue to cause you concern.
For any breast pain that becomes unbearable you can try applying warm towel compresses to the tender areas and take an anti-inflammatory pain med. when needed. Wear a supportive, but comfortable bra (sports-bra's work great!), that aren't tight. I hope life continues to get better for you ~ Take Care.