Its urgent!!!

Now that u have put in your valuable years in doing articleship, no need to leave ca even if u dont want to do it.  At least PCC to clear karo, just one grp is there, then after that you can make a fresh planning for finals.  Regarding CS, u can start it along with ca,  It'll take some extra effort and hard work but its not that difficult.  As your articleship is going to end in 5 months you will have sufficient time (if u r not doing anything else).

Regarding salary. its subjective matter depending on your skills, knowledge, city and a bit of luck still in North India an average student can expect 18,000-25000 p.m. as a fresher.