Alice gave very good links.
I'm sorry you're going through this - the loss of a goat can be heart wrenching, but as Alice says - they are not an easy animal to keep and there is a pretty big learning curve. Good goat vets and mentors can be invaluable. The group of experienced goat folks here have helped me tremendously -- come back often, ask questions.
I'll add -- to control parasites (IMO) requires a multi-pronged approach -
Fecal testing so you know exactly what parasite(s) you're fighting. I use MidAmerica Ag Research. Their tests will also include results for coccid.
http://midamericaagresearch.net/instructions.php
Coccid treatment in young goats - and in my case I have one doe that periodically shows up with coccid, even as an adult.
Nutrition - good quality hay, goat specific minerals, and we include Thorvin kelp.
Treatment knowledge - for example if you use Corid to treat Coccid, you need to know it's a thiamine inhibitor.
Parasite lifecycles -- parasites shed into pasture can be picked up and reinfect a healthy goat. Infected bedding can be problematic.
You can get additional education at WormX by the ACSRPC - American Consortium for Small Ruminant Parasite Control. My vet is a member of the ACSR - and years ago suggested using combination dewormers (second link below to the article) and it helped.
https://www.wormx.info/dewormers
https://www.wormx.info/combinations