Hello! I feel sorry to see the score there, Main problem among all others is images as you have noticed already. There are two approaches to address this issue. One would be to minimize , use less images. But that will be a compromise in image quality and overall design. Another option will be to lazy load images same way BBC does does. First load an placeholder then load actual images with JavaScript/ajax later.
All other issues I can fix like compression, browser cache etc.
I want to discuss, if I may, the image part about which will you prefer the most?
Please find me on chat, we can have further discussion there.
Thanks!