Secure (HTTPS) to non-secure (HTTP) pages don't work!

I’ve searched this forum to see if anyone else is having the same issue that I’m having. But I haven’t found any. If a solution exists, please direct me there. Ok, here’s my issue…

My site is hosted on a VPS server and currently being developed. I am taking advantage of 60 demo CS Cart, and I am going to buy the license in a week or two. I have turned on SEO module and it’s working fine. I have purchased an SSL Certificate for my domain and today I have installed SSL and it is also working fine until when I try to go back to an HTTP page from my Checkout Page, which is HTTPS. If I try to go back to my home page or any category/product page, it goes to HTTPS url, instead of HTTP. And when it does, I see a blank/empty page without any content.

Can anyone please walk me though how I can prevent this from happening?