To your working 15hrs a day to do this, I will tell you want I tell all my junior/middle level devs "Nobody is going to build you a statue" I e. don't break yourself for a company that will drop you without a thought if they decide it is best for their bottom line. You are with yourself for your entire career, the company you work for is usually transient (few people work for just one company for life these days).

Learn what you need to learn both in coding skills but also in your own process and self management skills, don't depend on anyone if it's something critical to you unless you have oversight and the time to keep chasing it

Could ai help de "obfuscate" these decompile results? It might help if you give it some examples, e.g. make some quick Kotlin code to cover a technique without having to go into the detail of your codebase and then also give it the koin/compose results of the same then your jadx results. Also try both on full code base and also on smaller sections, some of your core reuse code/patterns first might give it more grounded code. However may also be better to try to resolve the more complex elements. Consider trying a mix of techniques.

Although it might just be quicker to throw it away and start again and just use your apk to blag through the client call.

Depending on how well you trust your manager or you feel they have your back (unfortunately far too little these days) going to them with a plan to deliver in the call/meeting and resolve long term delivery may help you. But from the sound of it your company doesn't seem to care much about doing good/well/right just fast.