CBSE 12th

First of all, if you address your current predicament as phobia then it'll worsen your situation. don't panic or get afraid. Physics is most student's nightmare. It's because they believe it without even giving it their best. Here are my pieces of advice for you.
1. Tell yourself that the optics part isn't that tough. boost your self-confidence.
2. First get the theory part clear. if you're having problems doing that all by yourself then take help from online tuition.
3. Read through online resources. Sometimes the bookish language is tough to understand for students but even in exams, it is highly recommended to write answers in your own language.
4. Take Free Trial Sessions From Online Physics Tutors for unprepared or tough topics e.g Optics.
5. Optics part is mainly based on theory and the numerical questions are based on the theory as well so read and practice each derivation at least 4-5 times a day.
6. Take a Break in between your preparation. Don't overexert yourself more than you should. Remeber this phobia is all in your head and it won't go away until you treat it accordingly.
Best of luck.

The selection of candidates for Ab-initio (PPL) to CPL Course at Indira Gandhi Rashtriya Uran Akademi, commonly called IGRUA is done as per merit compiled after Written Test, Pilot Aptitude Test and the Interview. Written test is two hours test consisting of questions on General English, Maths, Physics and Reasoning (10+2 standard). The successful candidates in Written Examination undergo Pilot Aptitude Test and Interview. A merit list is prepared for different categories of candidates as per GOI guidelines and the shortlisted candidates are issued Instructions to join in batches for effective utilization of IGRUA resources. Refer: http://igrua.gov.in/Selection Procedure.htm