I honestly don't even know how to describe the scenario of what was going on after his death, however I'm interested in the fragmentation of his empire and would like to expand my knowledge on it. Any advice?
One very good book on the topic is Robin Waterfield's Dividing the Spoils: The War for Alexander the Great's Empire.
It covers the entirety of the wars of the Diadochi and goes very into depth without being dry, it's quite good and I really enjoyed reading it.
For a fictional book but one that is still quite a good introduction to the subject, read Mary Renault's Funeral Games. It's the third book of a trilogy about Alexander, but it could be read out of order.
The Wars of the Diadochi are a fascinating topic that is often overlooked, and should you find any other good books please let me know!