Certain websites not working after switching providers, help

A little background. I'm not the most literate about computers in regard to their technical aspects. We live out in the rural country, and thus don't have a lot of selection in regard to ISPs, it is either dial-up or satellite internet.

We were with Wildblue/Excede for roughly 7 years, but we got fed up with the low data usage cap (25 gb is a joke, and that was the highest cap) and switched to DISH internet (a bit slower but we now have a 50 gb cap). The satellite modem is hooked up to a netgear90 wifi router (if those details are important).

However, since the switch, I have been running into problems that didn't exist before the switch, mainly connecting to a few websites that worked fine previously. Almost all websites load fine but on certain websites I can't sign into them or upload things onto them (the loading wheel keeps on turning for minutes with no progress, refreshing only logs me out). I have to borrow a friend's Verizon 4g jetpack in order to do certain things like uploading pictures or logging into my college's student website.

I have looked at other forums where people vaguely had the same problem. Some have suggested it is a DNS problem (no clue what that means, not savvy in the computer lingo). Some online guides have said the dns can be changed in order to speed up the internet. Could it be that or something else? If there is nothing I can do to fix this, would utilizing a proxy server circumvent these issues?
Thank you for your time.

Using windows 7, 64bit OS on an Acer Aspire computer.