Iu widgets

hello everyone, i am in the process of making a training sim. i have pdf manuals that i want to include in the program so i converted them to png. i made serveral ui widgets with scroll boxes in them to make a “BOOK” if you will. now that i have done that my performance has taking a major nose dive. i now take about 5 min staring at a black screen before the program even loads. is this normal and or can i do anything to improve it?