Urgent and compelling personal reason to leave a job and collect unemployment in MA?

Although the only way to find out for sure if you are eligible to collect unemployment insurance is to actually apply, I think you have a good shot. As you know, the general rule is that, to be eligible for unemployment, a person must become unemployed through no fault of his own.  That often means the employee must have been terminated to collect benefits.  However, under Massachusetts General Laws Chapter 151A, Section 25(e), a person who must leave his job because of "urgent, necessitous, and compelling circumstances" is deemed to have left involuntarily and may be eligible to receive benefits.  Although there are no rules etched in stone about what constitutes a compelling personal reason, precedent suggests that your situation may qualify. 

In prior cases, workers who have left a job becasue of a personal illness, because of an unexpected loss of child care, to escape domestic violence, or, as in your case, to care for an ill family member have been awarded unemployment benefits.  You can read these cases for a bit of context:  Raytheon Co. v. Director of the Div. of Employment Sec., 364 Mass. 593, 307 N.E.2d 330 (1974); Zukoski v. Director of the Div. of Employment Sec., 390 Mass. 1009, 459 N.E.2d 467 (1984).

One important caveat to the above discussion.  In cases where a claimant argues that a compelling personal reason forced him to leave his job, he may be obligated to demonstrate that before leaving the job he made reasonable efforts to explore other alternatives, such as a leave of absence. This requirement may not be applicable in cases where the claimant believed no such leave was available to him or in cases where the leave would not have solved the underlying issue.  Hope all of that helps.  Good luck.