Cannot log into wp-admin

Hello,

Since I activated the plugin I can’t log into the wp-admin. I get this message when I try to go to my site:
The “mysite.com” page isn’t working. “mysite.com” is currently unable to handle this request. HTTP ERROR 500

Can you please help me to solve this problem. I deleted the plugin in FTP server, but I still cannot log in and I don’t know what to do next.. :/ The site is working just the problem is that I cannot login and do any changes.

Please help me with this and thank you in advance!
J

https://wordpress.org/plugins/ppress/