Internal server error when logging in

Hi everyone… I hope someone here could help me. Thanks in advance. ??

I just created a new WordPress site, and in the course of its creation, I configured some settings, created a new administrator (deleted the default “admin”), uploaded some plugins.

Everything was going well until I was about to activate all the plugins that I’ve FTP’d (about 20+ all in all). I was shown a 500 Error (internal server error) when I clicked the “Activate” button.

I logged out, and upon logging in, I still got the same error.

I contacted the support staff of my hosting.. and please allow me to post how our conversation went –>

Me: “I can’t login to my WordPress account (by going https://the2ndopinion.info/wp-login.php), but I can visit the site.
I am redirected to a 500 error.
Please help! Thank you. :-)”

Support staff: “Thank you for contacting our Technical Support Department.
I have tested your link and I do not experience any problem from our end. Please clean your browser cache and cookies and try again to access your WordPress: https://the2ndopinion.info/wp-login.php)
Also I can assure you that we do not have any server side problems which can be the reason for the issue that you experience.”

Me: “Hi… Thank you so much for the quick reply. ??
I did what you suggested but I’m still getting the same result. I tried using other browsers (Opera and IE7; I was using FF3 first time around) to no avail.
I even restarted my laptop.. it’s still giving me the 500 error.
Help please! Thanks :-)”

Ss: “Hello, …In this situation please try to access your site using the different computer and Internet Service Provider. Because probably your connection to our server is blocked somewhere and therefore you experience this issue. If the problems still persist after this test please contact us again.
Before this I would advise you to try again to access your link via Firefox browser: https://the2ndopinion.info/wp-login.php”

Me: “OK, so I used a desktop to try to log in to my WordPress site.. still couldn’t get in.
I couldn’t try your other suggestion (ie. connect to the internet using a different ISP).. I’m too far away from the nearest internet cafe.
I did some Google search and one of the sites that came up said this about the 500 error: “This error can only be resolved by fixes to the Web server software. It is not a client-side problem. It is up to the operators of your Web server site to locate and analyse the logs which should give further information about the error.” (from https://www.checkupdown.com/status/E500.html)
Are you 100% sure there’s no problem on your end? Just asking. ??
Again, thanks for the speedy replies…”

SS: “Could you provide me with the administrator’s login details. So I will be able to test to login from my end.”

Me: “my username: “Dr. Darius”
my password: “[my password revealed here]”

SS: “Problem is that chosen user name contains a blank space. Please provide me with another user name. I will update the WordPress settings. So you will be able to login.”

Me: “Really? But I was able to log in several times yesterday and the other day using that username and password.
Anyway, I don’t have any other registered user aside from that one, since I deleted the default “admin” user.
If you have to create a new user, please just remove the blank space, so that I could still have “Dr.Darius” as my username.”

SS: “I’ve removed it. But the problem hasn’t been resolved. I would recommend you to contact WordPress support staff regarding this issue. They will be able to help you: https://www.ads-software.com/support/”

Which brings me here. What’s going on here? Please, please help me! Thanks. ??

Dr. Darius