Procedural programming is a from the past and has limited use. Because the computer restrict the choices and actions of an enduser and therefore know where it is going and what is going to happen, makes it seems more easy to implement.
However with Xojo, that will never be possible. Very long ago, I also used procedural programming which I was very good in. Making the switch to OOP somewhere around 1995 gave me headaches and let me believe I better stayed with procedural programming. It took me until somewhere 2004 or 2005 when I switched definatelly to RealBasic (later RealStudio and now Xojo) that after a long while I grasps true OOP programming. It took me still some years to master OOP on the level I intended to master it. I still have very much to learn, even after more than 10 years using Xojo.
But I know one thing for sure : I do not want to return back to procedural programming ever again. With OOP so many interesting things are possible. It is possible to build so much Artificial Intelligence in your applications, which are simply not possible without OOP. Your end user can do so much, feel free and in control. And when you do things the correct way in OOP, it will make your programming life much easier and interesting.
Don’t give up on OOP, follow a good coarse (I follow coarses at Udemy which are very good) and believe in yourself. Believe in the goal to master OOP and Xojo. Xojo is so much better than PureBasic you mentioned. But for all those goodies to come true, there is a steep OOP learning curve. We all once get through that, nobody of us received it for free. We all had to learn, fall and standup again.
There is very good support here in this community. People will help you understand and learn. One day, you will be happy that you learned OOP because there is so much more possible with it. Back in 2005 I also almost have given up. But it was my determination, persistence and persueing perfecting my development skills which opened a bright new world.
I also read books about design patterns but I do not apply those design patterns by force. I do not say that I do not apply design patterns but my design patterns are inside my head. Nevertheless I do a lot of planning and thinking before even writing a single line of coding. Taking long walks, thinking about all facets of the application, how to implement its features, how the end user wants to interact with the application. When I am ready with that, I start creating the application itself. It may sounds unusual but it works. Even when I walk, I work! My wife (which is very much the opposite) became used to my behaviour because she knows that it leads to succesfully create solutions for our end users. And we do not have the need for a website of having clients.
Only you can decide for yourself if OOP is something for you. Make a good decision for yourself and once made persue your dreams and being the best in what you believe it is your way in making things done.
Wish you very much luck and all the best. Hope to see you again in the Xojo community, which is here to help you making your life easier.