When I saw your post it brought back recollections of my first email provider... and it worked great back in the 90's.
I don't know how many I've used since then. Choose gmail these days only because my outlook settings are messed up and I can't use it... it has so many features I loved.
I digress - just googled juno and find that your complaint's one of the most common and one of many about juno.

https://www.consumeraffairs.com/internet/juno.html

Your settings within juno or within internet options could be why you're having difficulty. Your anti virus Windows Defender is disabled so it shouldn't be affecting your loading juno.
Until someone can offer you the advice you need I'd be patient, try to access your email and save everything you want to keep. And begin looking at your other options for email providers.

This site is probably your best option for finding help.

 

I've used Juno since the mid 1990's.
On my desktop computer every day from a cold boot, I have to wait and wait and wait until Juno loads. I use a bare interface with no ads and I do not use the Juno page as my start. I'm using "classic". You can't get much simpler than the sign in page I use.
It has to be on Juno's side. So I wait patiently. Later, the load time is fast.