Change what you watch. That could do wonders for you. Watch girl solo stuff. (or guys but for sake of examples I'm saying females) Softcore porn. No men to be compared to.
Hentai or SFM (source film maker) stuff is all 100% fake wonderful bullshit. Less likely to get insecure over it. Might be wise to avoid NTR/Netorare if you are dealing with inferiority insecurities. NTR = cuckold.
Watch amateur porn instead of pro porn. Waaaaaay more average size dicks in amateur porn. Way more average sized dicks than big/huge dicks in amateur. Typically more realistic women. That is a bonus as you will be less likely to have unrealistic expectations.
Try photos (not gifs), audio, or literotica. These are all low bar stimulus. Porn is high bar, meaning thats a whole lot of stimulation being shoved into your eyeballs. Too much of a good thing leads to desensitization. Meaning you need more and more to get the same effect.
Avoid compilations, that is like porn but on steroids.
You could always cut porn out all together and just use imagination. That realistically the best option. Though I would work down to it through lowering the stimulus slowly like. Pro porn - amateur porn - solo videos- amateur solo - photos - audio - literotica - IMAGINATION *forms rainbow* High left and low right.
Odds are if you can't bring yourself to quit it... you have a problem. Such as talking yourself out of it by. Making excuses. Flat out refusing. Quitting but going back just for "a bit" . Quitting and to a flat out binge fest. Basically you can't stop in some way you always come back or never leave period.
Lots of men have insecurities. Insecurities are normal. Insecurities are also unsexy as fuck in general. Work through yours, destroy them. That will put you leaps and bounds ahead of the pack. Big dick smig dick. Your confidence >>> his dick size. Makes you more secure as a person, as a man. Realize size is all relative. Men and women vary. Some sizes work better on different people. You simply cannot be perfect. If you are perfect for one person with your 8x6 man slab you may be absolute shit to someone with a much smaller set of genitals/orifices
Take steps to start improving whatever performance issues you may have. If they are unfixable, learn get arounds. Get creative, how can you still fuck even though you have this issue? What could you do to make it less of an issue?
I don't know exactly what you mean by body issues because depending on how I interpret that, it could mean a number of things. Do something about them if they are something like your health or you are unhappy with how out of shape you may be. If it is something like your nose, like something that is just aesthetic. Learn to not give a shit. Love your nose, its longozzy's nose, its fucking awesome. If it is something that is medically wrong with you, learn to work with or around it. If genuinely have a deformity that cannot be realistically fix or something like that, you are going to have to take that on the chin and realize hey there isn't really anything I can do about it, so I'm not going to give a fuck about it. Letting it eat me up only makes me feel bad which in turn makes me adopt poor body language and give out negative signals. Self cockblocking. Instead I shall compensate with confidence, sexual know how, humor,skills, etc.
There is your solution to your porn issue and there are somethings to think about concerning your other issues. Hope you get something out it.