My iPhone 6 front camera is not working

I am using iPhone 6 now and my front camera is not working, sometimes it works but most of the time it doesn't. I belive that I am having issues with the software. I also tried opening my front came with other applications such as Instagram, but the front camera still doesn't work. I realized the front camera is not working on 24th March, the last time I used my front camera was on 19th March where I used the Instagram filter and it worked just fine. I updated my software to 12.4.5 a few months ago, however, last friday my friend suggested me to downgrade it to 12.4.4 to see if this method can fix the front camera problem. Unfortunately, it doesn't work at all. Can anybody help me. Please