Need advise. Abs,brake light, and check engine lights on..

So i have a 2006 prius with just under 125k on it. I have been driving with lights on for a week or two. I stopped in to autozone a week ago and they pulled the code p1121 ans said coolant control valve.
Heres the issue most of my problems im getting is with the brakes. Sometimes when i turn the car on and put in to gear whether its drive or reverse it just rolls into gear and have to reapply the brakes.

Now there is a long beep when i open the car door and or when i start. At that time the brake pedal is super stiff. Yesterday this happened while driving on the highway and lasted longer than the normal 10 seconds. I got off the next exit with a stiff nice person pedal. Was a little scary.

So ive done research for hours and i think (from what i looked up) that its the abs booster. So i decided to take it to the dealership and all they came back with is the damn p1121 code and says its my coolant control valve.

Just dont see how im getting such bad brake problems,the beep, forgot to mention the clicking/running sound after i turn off or while sitting when the cars on. (Sounds like its trying to charge the system?)

Please let me know if u have any advise to what to do. Cant afford to fix both as the ccv is 600 and the abs pump is 2000 plus

 

Thanks forgot to mention that. It was reading 11.8

 

How so

 

When not in ready mode it reads 11.8
When i turn it on and in ready mode it reads 14.1

 

So would you recommend changing that. Then what. Clear the codes and see what happens within a day or two.

 

Seems as if i have more than one problem..?