Hi Sona --
You've had so many changes along with the loss of your dad; sounds like you have done so much in the last few years to keep yourself on a healthy track mentally and physically.
So often stress and uncertainty seems to drive those with opposing viewpoints to, well, being more opposite, doesn't it? Which in turn adds to the stress, I know. There are so many great thoughts and strategies mentioned by YLFers upthread; I hope you are able to find some things that work for you/your family.
Keep talking, keep trying....
Unfortunately, I think the economic news is such a trigger for the very frugal right now. And it's not doing much for those of us who tend to feel guilt about spending on "unnecessary" items, either.
IME with the very frugal, there will never be a "magic number" or "enough" in savings. The security blanket is never large enough.
I would agree there is likely a backstory/unconscious need that your husband would benefit exploring, but I'm not going there and I doubt you'll get much traction either...instead, I'd focus on strategies/creating and reinforcing your boundaries.
So: I would think about talking to your husband about what percent he thinks you should each be saving, and what you ARE saving. [The plus side of being with a compulsive tracker -- you have the latter number at your fingertips!] Obviously this number is very large.
Then tell him you understand his preference and his desire to protect your family, but you feel right NOW X% to Y% [make sure you give a range!] is the number that works best for you in terms of enjoying life and protecting your future.
That gives you some negotiating room (remember to keep your final percent to a range, and I'd suggest percent vs hard number).
Remind him that of course you can revisit your range anytime a financial expenditure/crisis comes up. And maybe set a regular time to do this (every 3 months? every 6?) and check in with him so he feels he's being heard.
Echoing others, I'd just have this money direct deposited from your paycheck to another account.
Personally, I wouldn't have anything you spend from that account tracked in the joint Mint. The Mint can reflect the money is going INTO your personal savings but not what goes out...because really, ANY "frivolous" spending you do will just give him anxiety and keep the good/bad dynamics in play. [Create your own tracking system/Mint account if desired.]
Wishing you continued luck with creating a happier, healthier life!