Maybe try the performance CPU type for now, to get out of severe degradation territory; those will definitely work.
Then later inch down gradually with the shared class (the cheaper ones subject to these quotas). If things were doing ok until just recently then there likely is some vCPU count that will do the trick…
Aside: @Hypermind’s proposed mid-range flex class would be a better fit (I’m guessing)—but it unfortunately doesn’t yet exist…