feeling like a monster, pocd.

I am a porn addict, been masturbating since when I was like 10.
there was this one video, in which the girl would wear school dress, and I would masturbate to it because the girl looked similar to someone my own age. I am pretty sure it is not illegal as it is in one of the most popular tube porn site out there, and I am pretty sure they won't allow any underage, and the video is there for around more then 5 years and can be accessible with a simple google search, and I know google don't allow if the image contained child.
also sometimes, I would watch some videos in which people look younger just because they look similar to my age.
I never thought anything sexually about someone who is below my age range.
but recently I start to obsess what if the girl is underage, and I can't stop thinking about it

I again gone to that video, but this time I cannot masturbate to it because it make me feel very anxious, so much that I got a chronic pain, just with the thought that the girl in the video might be an innocent underage girl.
but this further increased my uncertainty as I saw some one in the reddit said that your attraction won't lose, this just makes no sense, as when I imagine the girl as underage, I have no desire to masturbate and getting anxiety, but I was previously masturbated to that video
also did I mentioned that the video is one of the most popular video on that site.
now when ever I see something that looks like underage, I am asking questions like will you have sex with them, which gives me again chronic pain.

I gone to that video again, and asked myself questions like

are you aroused ? and I felt like yes, which freaked me out.

recently I saw a movie scene in which there was some guys who actually strucked a camera in a school girl's toilet, I suddenly imagined myself in that situation, and then I got groinal response, and felt like I would do it if i want to and get aroused by it. I am freaking out.

I feel like killing myself is the only way out.

I don't know what to do honestly.

I some times, feel like suicide is the only option
thanks again if you took your time to read this post