A good place to start is here
https://www.ehealthinsurance.com/ You can only buy health insurance that is registered in your State. That is why that link is a good place to start. They keep no personal info, until you get your choice through them. The don't seem to show Humana, so that might be one where you do a specific query for a quote.
According to Obamacare, previous health conditions or current health conditions no longer matter to insurance companies. This is in relation to preexisting conditions. So, insurance companies don't share claims. They are highly competitive, so they won't be helping their competitors. Mostly, quotes are competitive as well, but in relation to what services they offer. You will see that they are all similar in price. It's the service that makes the difference. One insurance company will not tell another that you have requested a quote.