Opencart admin not working after activating SSL

I am using oc 2.1.0.1. I recently added SSL for my site. I activated the SSL on option in opencart setting.
Modified the config.php and admin/config.php and added the https version of the site in the codes.

the front end login and checkouts work fine in ssl, but when i login into admin panel and click on view orders i am getting an error undefined message. I am unable to change order status.. every thing else seems to working fine.
I tried deleting and adding new api user.. still the problem persists.

I also tried https on all urls admin/config.php and config.php and it didnt work
Also tried to implement full https by doing an 301 redirect from .htaccess

When i disable ssl for admin from admin/config i am not getting any error.

when i do inspect element in chrome for the error its showing the below error,

jquery-2.1.1.min.js:4 Mixed Content: The page at 'https://mywebsite.com/admin/index.php?r ... er_id=2276' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint 'http://mywebsite.com/index.php?route=api/login'. This request has been blocked; the content must be served over HTTPS.send @ jquery-2.1.1.min.js:4
jquery-2.1.1.min.js:4 XMLHttpRequest cannot load http://mywebsite.com/index.php?route=api/login. Failed to start loading.

What i ideally want is a site wide ssl using a 301 redirect.