Why Is Apple Not Allowing Me Access to Music I Paid For?

I began purchasing music from iTunes in 2000. I have had three email accounts over the last 30 years and all three were associated with an Apple ID. Unfortunately, one of those email accounts was through a cable company I no longer use (and haven't used since 2004). I no longer have access to that email and when I answer the security question correctly to try to reset the password, Apple tells me it is incorrect when it is 100% correct as it's a past pet's name that I would never spell incorrectly. This issue of not being able to access music happened in 2016 when I bought a new MacBook Pro and Apple told me it was resolved (and I can play all of the music purchased via all three email accounts/Apple IDs on the MacBook Pro). I recently purchased a new MacBook Air and once again this problem has happened and I cannot find any work-around to access music I paid for and also my new MacBook Air is not being allowed to be one of 5 authorized devices on my Apple iTunes/Music account (limit is 5 and I only have an iPhone and my old MacBook Pro as authorized so I should be able to authorize a third device). I find this very frustrating. I regret ever purchasing music from Apple. I am having many issues with iTunes/Music on the new MacBook Air and think I should return it. Nobody at Apple wants to help so I am asking the community. I learned my lesson and will never purchase music or movies from Apple ever again. For the record when people pay money for something, they should have that product or service--to be denied is unethical. Thank you.