I feel your pain. I was in a very similar situation when my husband was in pornography addiction mode. I felt that I could not compete with the women on the internet, despite knowing that they are a fantasy. It took me time and extra help, including this site, to help me realize that his compulsion had nothing to do with me. It sure doesn't feel that way at the beginning, though.
Internet porn is so stimulating, that it can cause porn induced erectile dysfunction in men, which means that they can't have sex with normal humans. Women are objectified and, as objects, require no emotional attachment. What makes sex so special between people in a relationship is the emotional connection. Sex addiction is a coping mechanism, an escape. Emotional connection is not the objective. When the porn that a sex addict is looking at doesn't work to get them off, they move on to more "intense", explicit pornography or affairs, or massage parlors, etc., to get their needs for escape met. The ritual and the fantasy surrounding porn are compulsive. Porn addiction, like any addiction, progresses until the user suffers enough to reach out for help.
Living with an SA is a rough road. My husband is a drug addict with 27 years of sobriety. He is also a sex addict. He has maintained sobriety from drugs and alcohol , but has had some minor "slips" with regards to sex. Although he did not physically cheat, both of these revolved around online content. After each slip, my husband recommitted to sobriety. He has been able to remain sober for 2 years. For perspective, it has been almost 8 years since DDay. Online pornography was the catalyst that precipitated my husband's downward spiral into a physical affair. The use of the porn continued through the affair non-stop. TBH, my husband was lucky in that he was caught before he escalated further and completely destroyed his life.
It took me a while to be able to enjoy sex without comparing myself with the online women he was looking at. I was in therapy, which helped. The actions he was taking to become a person with some integrity helped. His ACTIONS which consistently showed some true remorse helped. My anger also helped, because I was able to say "F it, I am going to get mine and I cannot worry about his fantasy life". He continued to show me that he wanted a marriage to me and that he wanted me as a sexual partner, and, given time and self-work, I have been able to believe it. I am now older and wiser and less inclined to participate in bullshit, and I am happy with myself. This most important change in loving and respecting myself and demanding the kind of life I deserve has been a game changer.
In order to maintain sobriety, there are some things my husband must do on a consistent and long-term basis:
1. 12-step meetings and willing engagement in the process of recovery. If your husband is not fully committed to the SAA program, attendance at meetings consistently and for the long term, getting a sponsor, and doing the work necessary to maintain sobriety, he will almost certainly relapse. The relapse rate is high for all addicts and especially SAs. Because of this, my husband also attends AA meetings. There are many people in AA with a lot of sober time. It is always worth listening to them when dealing with any addiction. In SAA, there are not many people with long term sobriety. IMO, this is because SA is a process, or behavioral addiction, like gambling. With other addictions, abstinence is the answer. For example, I have been in recovery for alcoholism for many years. I abstain from alcohol. If I had to take a drink once a week to maintain my marriage, I would relapse. For an SA, the very behavior they are addicted to is necessary for a healthy relationship. This makes it super hard for an SA to stay sober. SAs have to focus on compulsive sexual behaviors vs healthy sexual behaviors. There is often some sort of overlap there. This is why attendance at SA and AA meetings is part of my husband's repertoire for sobriety.
2. Therapy with a CSAT. My husband goes twice per month. A CSAT helps him to develop the tools necessary for sobriety and to develop healthy coping skills, both of which increase my safety. Your husband NEEDS a therapist who has experience with SA. Most of them do not. This is a non-negotiable in my opinion.
3. Lifetime commitment to sobriety. This means that your husband will need to be actively attending meetings, and participating in all aspects of a 12 step program forever.
4. Willingness to tolerate oversight and loss of privacy. Your husband will need to allow you access to all online activities in order to give you agency and to ensure that you are safe.
5. If he is new to recovery, then your husband should not be online unless you are awake and present. Based on your post, your husband is not able to safely use the internet at this time. An SAA sponsor should be working with him on his circle behaviors. These will help him define the "slippery slope" behaviors he needs to stay away from, and the compulsive behaviors that he cannot engage in at all, like watching porn for my husband.
As I previously said, living with an SA is hard. You cannot bargain with him into or make him get sober. If he is not willing to reach out for help himself, and participate in it consistently and for the long term, it might be best to move on for your own sanity. Living with a using addict is chaos and misery. If I was not an addict myself, with the understanding I have of addiction and sobriety, I am not sure I would have been able to manage it, TBH.
I hope this post has been useful and I wish you well going forward.