[R-SIG-Mac] R will not open

[Gow, Elizabeth]

I have downloaded and removed R (various versions of R 3.X.X) from my Mac (10.9.5) numerous times and R will not open. When I open R from the icon in my application folder, the R console window opens and then says loading at the bottom, then after about 5 min it freezes my entire computer. I’ve tried installing multiple versions of R and nothing works to get it to run. I can open R in terminal. I’ve spent hours searching through the forums but am not finding anything that works. I have removed every single R associated file on my computer and then reinstalled R and it still does not open. 
One day R was working and then the next it was not, so I have no idea what happened and why it will not start. 
I have no error messages because it will not even open. 

I do not know what to do? I need to R everyday for my research. 
Any suggestions on how to fix the problem would be much appreciated, thanks.