With the anniversary of your husband's death coming up I'm not surprised you're feeling rather emotional, especially with everything at work as well. My sister lost her husband in March to cancer and it's ripped her life apart, and I can see it's something that will take a long time to heal. 2 years is a very short time, and I'm sure you are still fragile.
I have to be honest, to have got through a bereavement like that, bring up a son, have Bipolar and to have been holding down a job is blooming impressive.
As for the current situation, switch it on it's head so both situations are a win, you'll either be working which is a win, or working on your Masters, also a win.