I think that you can still apply for scholarships with a conditional offer.
You should probably buy the IELTS pricy books and take some classes before sitting the exam again. Apart from spending all that money for a useless certificate, it is not very hard to achieve a 7.0 at all the tasks. I think it is worth giving one more try.
I had to go through this procedure a couple of years ago. First time I only scored 6.0 or 6.5, therefore, the second time I had to take private classes with a friend. I used to work full-time at the time and usually I would go to the class without having completed my exersices :$ ... and she would look at me like that :-s. I was such a pig, I would not even turn my mobile off during the classes!
Refreshing my rusty knowledge a couple of hours per week for 2 months was more than enough. I was hardly in a proficiency level when I quit studying English a decade ago.
Once I sent the results, my offer turned to unconditional. Try to watch some English movies (without subtitles), read the english newspapers on your way to work.
Congrats for the offer and good luck with the scholarship hunting! (sprout)

Hello Nadoon!

I am making a wild guess here (having found myself in similar situations) but I think that the problem is neither the job or the PhD. At the end of the day it is your natural inhabitant! Working too hard for a prolonged period can make you feel exhausted, fed up, makes you want to run away.
In similar situations, where I feel I had enough, I try to take some time off. Sometimes going away just for a weekend and change the scene, stop thinking completely all about work, can do the trick. Try to build a pleasant routine:
exercise (find something fun to do twice a week), meet friends for a drink after work even if you feel tired, shut computer down at 23.00 no matter what, date people etc. Think positively: work can get hard, but at the end of the day it IS your choice and it WILL get better. Being enthusiastic and happy can make hard periods flow like water.
I quit well-paid jobs once they become really easy - not challenging my mental abilities anymore. I dread the day when writing will become easy. It will be time for me to drop everything and move on, learn how to built wooden ships, or make robots or anything new.
Enjoy it because it will not last for ever.