All my Browsers have been hijacked on my MacBook?

One night I tried to download this application off of the internet (stupid I know, I regret it). It lead me to this thing call "DownLite" I clicked on it and I believe and ever since my computer has not been the same. I've run a multiple of anti-virus scans and everything (my files and applications) are okay.

The main problem is my browsers.

I mainly use Google chrome. Whenever I use it, I get these annoying In-text ads, that are highlighted green and underlined twice ,whenever I'm on an article site. Whenever I use specific websites (google, youtube, wikipedia just to name a few) I get these ads and banners that bring me to other ad sites. Sometimes these ads are videos and it is extremely annoying

I opened up Safari to see if this browser is okay...turns out Safari is doing the same thing.

Ive tried almost everything! Cleared my Cache/cookies everything

I just really want this to end, it's extremely annoying! I am currently using "Ad Block Plus" to stop all the annoying ads, but I just want the situation to be gone permanently.

I've tried to change the default search engine and homepage but chrome or this "virus" is not allowing me

When I open a new tab the address is chrome://newtab which I've never seen before.

I definitely believe this is a google thing i'm not sure..

Thanks