I don't know what OS X Reserved is in your partition list, but unless you only set you BootCamp to be 8GB, the one titled BOOTCAMP is still your bootcamp disk.
Do you have a backup of your data? I will try and help you non-destructively, but I can't promise anything.
First off, install home-brew.
Now, through home-brew, install gdisk (brew install gdisk)
Now we'll use gdisk to get rid of your BootCamp partition, since Disk Utility won't.
First however, we need to remove System Integrity Protection temporarily, so boot into Recovery Mode (hold cmd+R whilst booting), and open a Terminal. Type "csrutil disable". Now (assuming no errors) reboot back into your system, and run
"sudo gdisk /dev/disk0"
type "p" to print your partition table, and locate the BootCamp partition.
Type d to delete a partition, and enter the ID of the Bootcamp partition. Then type w to write the changes to disk.
You should now reboot and be able to merge your APFS container with the blank space, with the command
diskutil apfs resizeContainer (size of container)