New Here - Some Questions I wanted to ask

Hi there. I'm a Male living in the UK. I was first exposed to pornography when I was aged 9. By accident. I watched it from the age of 9 a few times a week until by age 11 I was watching it daily. I know this is illegal but sadly it seems to be the new norm. It is awful.

Nobody showed me it. It came up on a PopUp and then I was hooked in.

For the past 2 years I've really disliked my porn habits. I've been masturbating 2-4 times a day on average, each time to pornography for the past two years. I felt recently that it was really getting out of hand.
I noticed this when I tried to stop, and couldn't. Just couldn't. I then realised I was an addict. I underwent irritable feelings when I stop. I've recently cut the cord again.

I have a list of 4 questions I was wondering if any forum members could/would answer.
1. Is there such thing as a "healthy" amount of Pornography to consume? I'm aware of the Dopamine pleasure reaction and the whole Pathways thing. I'm wondering whether much like other Dopamine fuelled pleasures e.g. Eating, Drug use, can be used in moderation at a healthy level? Like if I was watching it 1-2 times a week instead of 2-4 a day?
2. Is it the porn or the orgasm from masturbation that drives the Dopamine dependency? I have heard Porn can trigger dopamine release easily by simply viewing it, without the masturbation. So is Masturbation another part of the problem?
3. I've still been masturbating a lot. 2-3 times a day at this point. Not to pornography though. I've been using my imagination. I think the amount I do it makes me a bit uncomfortable with where I am but to me it is better than watching Porn but still not necessarily good. Should I try and cut the masturbating down and or phase it out?
4. Since I started watching it at around 9, and continued all through my teens. This means that I was going through sexual development/Puberty with Porn being such a regular thing in my life. How likely is it that this will have caused any serious sexual/mental problems for me?