If you really want to get a WC conquest going, feel free to MP me (I one tagged before last level of admin efficiency, in 1735 if I remember correctly). I don't want to be overly negative, but I think there are issues with the economy, especially the trade, the target prioritization, the idea groups and probably also the estates management, or else you could not have 0 manpower for 50 years and be behind in tech as the Ottomans. All of this can be solved, and EU4 has a very harsh learning curve, so with enough screenshots I could point your mistakes and help you to get over them for next time.
Doing a WC requires to master all the basics of EUIV, to be able to create a strong and stable empire by optimizing building, trade, estates and idea choices. And then there is another difficulty which is not to overextend and at the same time not to lose too much time, prioritize targets based on trade routes, alliances, future opportunities, religion and culture, dodge coalitions and play around truces and alliance webs. It seems you're still missing on the first part, at least to a certain extent.