Blank, you prompted me to install the game on my laptop. It was a lot easier last time, when I didn't have to fiddle around with dosbox.
And then it started a bit slow because I couldn't remember how to play.
I'm playing the second difficulty level and I'm now on Thursday in week 3. I think it's the same scenario as you, but the d-gates are clustered in the southwest of the map. Tall slum blocks get in the way and stop me getting clean shots at the alien craft. This week I haven't shot down any aliens and lost several vehicles. In the last invasion, a slum block was completely razed. I thought to myself "I hope I didn't do that". But Osiron is now annoyed at me.
On the ground, my X~Com has around 20 soldiers, including four mutants who stay in base as much as possible and three or four wounded who garrison my research base while they heal. I tend to take 12 soldiers per mission. They arrive on the map as two squads of 6 but then I reorganize them to squads of 2 to 4. Strong guys and androids get autocannons, accurate guys get sniper rifles which seems to train their accuracy even more, and a disruptor in their backpack for situations when fast shooting beats long range. Rookies get twin plasma pistols for the higher basic accuracy and everyone else gets twin disruptors. Whenever I don't have aliens to worry about and I notice my training facilities are overcrowded (effectiveness < 100%) it's time to get someone injured by raiding the cult of Sirius, or, as I like to think of them, X~Com's primary funding source. Another 6 or 7 raids and they'll have given me enough for an air hawk.
Large bio and physics labs are scheduled for completion early next week.
But the aliens are keeping me busy. Diablo are half assimilated so I need to annoy them by speculatively investigating their buildings. There's a handy button I haven't seen you use, Blank, over on the left side of the screen, that gives you a graph of the level of assimilation of different organizations.