As a rule of thumb, unless you are already financially independent, NEVER quit without first finding a job. You will spend all the days at home cold sweating waiting for interview calls and trust me, it will be worse than anything your boss can throw at you.

Just continue applying and hope for the best. Many bosses and companies are very strict in terms of discipline and politically correct when it comes to small talk, do not assume everywhere is like your former company where you can just brother brother crack jokes and make insinuations of quitting to anyone you hardly know.

Treat this as a lesson learnt. Anyway so far other than stiff culture, at least there is no unreasonable behaviour from boss or colleagues in terms of work, so you should try and get use to it and slowly take your time to assess your options.