Why won't it go away

Hey guys
It's been a couple weeks since I've posted here, my phone died. Anyway, I'm on my sixth week of no pmo, I'm losing count of the days but it's a little over forty days. I have to admit I've hit a plateau. The first few weeks were totally fine I found myself motivated to do a lot more around the house and help out a lot more. But up until recently early this week I've just been feeling really crappy. Very moody and I can't tell if it's all with the sudden urge to watch porn or partly to do with my situation at home with my pregnant wife.
Wednesday was my birthday and we had sex in the afternoon. But at night for some reason I just felt really horny. I did not want to watch porn and I even had the chance to and I told myself that I could. But I didn't do it. I don't know why for the moment when I went to my computer I got turned off by it. I'm really happy I had the will to just walk away but I did masturbate (first time since my last pmo). I didn't feel bad about it then and I don't feel bad about it now, mainly because I did not need porn to do it, and that I turned it down when I had the chance to watch it.
For some reason today this morning has been really rough on me. I don't know why I just want to watch porn. I just want to get rid of the urge to watch it every now and then, it's not as bad as it used to be before I started my journey. But I guess it's because back then I didn't really know I had an addiction. Now I know that if I do it I'll just be fucking up my progress.
I feel horrible because I'm starting to feel a little bit bored with sex, and I'm not even having it often 1-2/week. I wonder if it has anything to do with me attempt to stop pmo because I've never really felt that way before. It's not like I'm having sex very often, and when I do I'm totally turned on by it. I really think my brain is fucking with me, recently, I have the urge to have sex with other girls but I will never do it. When I see a hot girl I get negative thoughts which had stopped in my first few weeks but like I said it feels like I've plateaued. Is this normal? Has anyone ever experienced it?
I'm trying to get out of this small funk I guess this weekend I will work on the house as much as I can to keep myself as busy as I can. Like I said, the urge to watch porn is there but I can't go through with it. I think I would feel strange. I don't want to test it because I know I will feel strange at first but then it will be back to normal if I were to indulge. I just want the urge to go away and things will become a lot easier. I don't want to be thinking of sex and only sex when my wife is too pregnant to have sex with me or the fact that our sex life will dwindle a lot more in the next few months. The first time she was pregnant I was of course into my addiction and I even had the urge to cheat on her and I had the chance to, but I didn't. I literally had someone throwing herself on me and I didn't fall for it, and I'm so thankful for that.
I don't want to fall back into my pmo addiction, which is why I started when I did and I'm glad I started at that point, I guess the timing was just right. By the time she gets into her seventh month I won't be expecting much sex at all. And if I'm over this by then I would be 6 months clean. Which I'm hoping will be enough time for me to reset and focus on other things. I guess I'm afraid to fall back into that life and that's why I refuse to watch anymore. I didn't want to post anything but I remembered that every time I do I feel better, and I do feel better now. I'm just tired of being fine for days on end and then having one bad day or two in a row. Hopefully some of you can relate and maybe give me some advice or ways that you coped with this. Thanks guys I just gotta take it one day, one hour. One minute at a time, whatever it takes! I have to do it! Stay up everyone !