I can't access wp-admin and post to my blog

I can’t access my wp-admin at https://www.pressrun.net/wp-admin. The connection gets reset even before the page loads up.
I have a similar problem at my blog, https://www.pressrun.net/weblog. There I can log into https://www.pressrun.net/weblog/wp-admin. But I can’t post from there. I can’t also go into users, settings, profiles, plugins, themes or any of the other pages from the admin dashboard.
The trouble started after I changed the usernames two days ago. I asked my web hosting service for help. They changed the usernames at my request. They could enter the dashboards both at https://www.pressrun.net/wp-admin and at https://www.pressrun.net/weblog/wp-admin, create a new user and publish a test post. But I can’t.
I can see www,pressrun.net/on my browser, but I can’t post. Typing in the address automatically takes you to https://www.pressrun.net/weblog. That’s the way I set it up so I could use the domain name https://www.pressrun.net for other sites or blogs as well.
I can access all other websites. So there’s nothing wrong with my internet connection. I also deleted my entire cache and all the cookies. But that did not solve my problem. I also tried to post from WordPtess for Android but I couldn’t.
Please help. Thank you.