I think I know a solution. I haven't updated using this method because I messed up the stock recovery trying to flash CWM on it and failed so I'm not sure if it'll unroot my phone iif I do this and since my stock rom is out then I can't root it again. Either way this method is safe since it's an official firmware for this phone. I don't know if it patches anything or if you'll be able to root your device again if it unroots it but from what I can tell you don't have much of a choice unless you plan on getting a new phone.
First, see if you can do this; hold down the UP Volume button and then hold the power button until a white screen goes on, it should say something like "Updating with tfupdate.img" and after a second it'll say "no tfupdate.img found, system will reboot now". if you can do that then you should be good.
Now go to this website and click download and save; Downloads - Huawei Device Co., Ltd..
it'll give you a zip file, extract and copy the folder called "image" on to the root of your Activa SD card (use an SD adapter to transfer the files since your phone is bootlooping)
now do the same thing I asked you to do in the beginning, hold the UP Vol button and the Power button and it should update your phone. It will take a while to complete and on your first boot it will take a long time to load. After that you should be good.
If this works tell me how your phone is, if the update did anything, did it unroot your phone? etc.