Serey, as you have worked more than 365 days on CPT, i believe you will be eligible for OPT only if your working hours is less than 40 hours per week. Here is the conditions for CPT to be eligible for OPT after graduation:
1. Work full time (40 hours per week) in CPT but should be less than 365 days.
2. Work more than 365 days in CPT but should be less than 40 hours per week.

PS. I might be wrong but that's what I have understood so far..