Cars aren't worth financial stress period. As a 911 owner I'm often conflicted about the money I spent. Thankfully I can afford it and have no stress for now. Hopefully my job is not impacted by the pandemic.
Suggest you keep the M240i for now but save like hell to get your 911 as these are keepers for life. The good news is the 991 generation is proving to be pretty reliable overall. I hear used prices on 991.2's in particular will be coming down. I'd have no issues buying a well maintained, higher mileage one that has been gremlin free. There was a 991 Turbo with well over 200k miles posted on there a while back. Phenomenal.
Your down payment will grow while the cars will become more affordable and you can acquire with lower monthly outlay. Hell, if you're like me maybe you can even have both by then
Patience + discipline and your dream 911 will come.
P.S. I'm jealous of your B58 and am actually saving to do the opposite; add a B58 (but a 340xi 6 speed) to my stable
See how the grass is greener sometimes!