Reduce scouting to $0, saves $10k/week.
If the $500k you just spent is for the training court (improving FT), sell it. You only get $250k back but you don't need the FT improvement at this stage. That should put you into the positive if your current cash is -$200k.
As you've just had a home game, we can see the impact on prices. Reduce bleachers to $16, lower tier to $40 (someone else might have a more accurate suggestion, I'm not great with prices). Courtside and Luxury is maxed out even at max prices, so keep that the same price. When you have spare money increase those sections first.
Once all that is done, try to work out if you are making an income each week. If so, stick with it and you'll be fine. Maybe buy a couple of high salary players for very cheap (staying below the salary floor of course!) as suggested above. And also expand the arena whenever you can. Don't spend on anything else.
If you're not making an income, then you could downgrade the gym. If you downgraded all the way you would raise $500k, which I would advise spending on the arena. But only do this once you've tried everything else.
And I definitely wouldn't fire the youth trainer unless you are also selling the player. I've forgotten the exact impact it has but it's a lot, especially for a HOF+ prospect who needs every pop.