I used to do the same rat race but found a solution.

1. Book amtrak from providence weeks in advance. The tickets are cheap, like less than an MBTA ticket. You can cancel right up to last minute. $$ goes back into your account. No stops.
2. Park in the Providence mall. If you are on east side, ride your bike, etc. That's what I did when the weather was nice.
3. I also took the MBTA in and amtrack back, etc. Just getting home fast was great.

The Amtrack trains don't run all the time, but if you can time your work and it right, you can save hours. The downside is the cost of the garage in Prov vs. free in Pawt. But what's your sanity worth?