I managed to find some at the Costco in Nashua. A pharmacist told me they have a different supplier than the CVSs and Walgreens so they might be worth checking.

I live in downtown closer to Market St and have noticed that Jackson Street and Middlesex St east of South St is generally fine. The rowdy-ness around the Transitional Living Center is far enough away from the Jackson/Appleton lofts that I wouldn't say it's a significant factor to the safety of the area. Not saying the area is perfect, rather it's about as safe as anywhere in downtown. I experience way more unhinged folks on Merrimack St than around Jackson St.

I will occasionally do a full work day at Coffee and Cotton in Mill 5. There are always places to sit and it's a very chill and comfortable atmosphere with drinks and snacks. During the day Mill 5 is largely empty so I've taken calls by finding an empty corner somewhere on the 4th or 5th floor. They are closed on Mondays and Tuesdays though.