Unfortunately, it seems that researching Mathematics has lost you any

advantage that the Alphabet beeline could have brought.
This is because AIs research Maths so much. The tech has very little trading value. (And maybe you were too prone to gift techs for diplo bonuses ?)
I think that researching straight into Currency, or Aesthetics (trade bait) or Code of Laws (with Priesthood, opening an Oracle slingshot, maybe ?) would all have had better chances to maintain your tech lead.
Alpha beeline gains you beakers but loses you hammers. Better have those beakers count.
e.g. : you should know that you were lucky to settle 2 late cities near the SE jungle, especially getting the corn/copper site. The area is hotly contested by Churchill and Montezuma. I lost that corn before even 2000 BC.
@ Diplo : I'd aim to switch into Judaism without doubting too much.
Monty is the most appealing ally and he even has a Jewish buddy... the other warmonger...
@ 7 workers : you probably shouldn't go straight into that, without settling your remaining cities.
The Hague seems well-suited to produce your next settler (chop worker, then whip settler ?).
Getting more and better tiles to work asap is the stake. Some infrastructure, too, when growing doesn't bring much.
Having stronger cities does give some manoeuvrability, when it comes to choosing between war and peace. It may be best to keep your options open and see what's coming.
(To me, jumping into a war led by Montezuma seems like a nice and cozy way to capture a few cities and maybe, even, to take out a rival.)