cryptocurrency exchanges.

I was searching for a good cryptocurrency site to use fiat to buy, hopefully, more than just bitcoin and ethereum. I registered on coinbase, but am not enthusiastic about the multiple fees. so, I registered with bittrex. The problem with Bittrex was the overwhelming security to the point the double authentication actually broke down and didnt work. After that I was unable to use my email for that account anymore. This happened twice, so now 2 of my email accounts can no longer be used. I said to myself, you know, If I had had money or crypto in these accounts, I would be locked out with no recourse and my funds inside. this is ridiculous. The whole point of security is to safeguard funds, not lose them. What's worse is they have no phone number, just an email they never answer. Im all for security, but the bungling double authentication using the authenticator app. is to ridden with things to go wrong. Also no recourse to recover if the authentication fouls up. I guess Ill have to just stick with using coinbase and transfer crypto to a decentralized exchange after that Any suggestions would be nice...