I assume you know about the workshops+manufactories combo if you're going for a WC. And honestly, if you're going for a world conquest, you don't need to be making money that badly. Your economy will grow and you can pay off multiple smaller loans with bigger ones, and with enemy treasuries like the Banks of India, Bank of Ming and Bank of Russia. Especially not if you're losing half a ducat a month. With 3500 in your treasury at half a ducat a month lost, it'll take 7000 months (583 years) for you to take your first loan. You're fine.
Idk about idea groups, but I hope you have quantity for cheaper armies. As for army comp, delete your cavs. Just...don't bother with cavs. As Ottomans your army forcelimit is large enough that for every cav you have, you could have about 3 infantry for the same amount of maintenance. So delete your cavs, go up to 20 infantry and get a full 10-20 stack of cannons for faster sieges. In a WC your primary concern is time, not money.
Also at a loan size of 1500 and growing, trust me, you're fine. There's a burgher privilege that gives 5 loans at 1% interest. So pass it and if you blow through that money, you can revoke it and pass it again for another 5 cheap loans and use it to pay off the older loans that'll start charging you 4% interest (in absence of other modifiers) once they refresh, or just as a fresh infusion of new cash. Remember to pay off the largest interest loans with your enemy treasuries, get an inflation reduction advisor when possible and buy down excess inflation if needed (keep it below like 7-13% if possible).
In fact the only reason I can see you're truly losing money is the advisors and honestly that's not a bad reason to be in the negatives.