I'm not sure whether I can use these phrases interchangeably or not. One example is:
Gas prices are getting higher and higher, but I have to fill up my car anyway, because I have to drive to work.
I got a job offer, but it was canceled, so I have to start job-hunting again.
In these cases, which is the most appropriate sentence to append to those examples?
(a) "I have no choice" or
(b) "It cannot be helped" or
(c) "I cannot help it"
Is there is any difference in the usage between them, and, if so, could you explain it, please?