Is this situation a lost cause?

[Simple Machine]

Qin is going to space, and I cannot easily reach his capitol. I only just got to tanks, and he has modern armor...

 

[civac]

Yes. This game is done. Qin doesn't have much military but only needs 2 techs to go to Space, 3 if he researches Stealth. Your only have about 60 real units, no fleet and lack tech for either artilley or nukes. There is no way to build an army + fleet and deploy it in time. The fastest way to get to his capital may be nukes + paratroopers but that probably takes too long too.