Try QED: The Strange Theory of Light and Matter by Richard Feynman. The Kindle edition is $9.99
If I may, let me suggest that you watch the two below referenced videos. The first one is presented by Dr. Don Lincoln of Fermilab. The second video is presented by Dr. Sabine Hossenfelder. Frankfurt Institute for Advanced Studies. Neither video gets into the math, which is hard, but do manage to give you two opposing thoughts on the same topic. Both videos use the same example (precisely the same example, actually) but draw different conclusions.