Don't do porn. Simple as that. It's exploitative of the bodies of women and lust in men, you don't know how to do it, you're not at ease with it, and it's tough to do. BUT, there are all kinds of other sex related sites you can do that are not saturated.
There are 'hard' sex sites that directly encourage lust, swinging, and immodesty/sluttiness such as porn, adult personals, sexy swimsuits (which are worn in public). There are also 'soft' sex sites that deal with sex without such advocacy, like general personals, sex pills, sexy toys or lingerie (which are used in a private context). Putting lots of sites up on these lines can tap into the sex markets without upsetting your morals.
Choose the option you can live with, making a judgment call on what you can do. Can you run a site with pix of fitness models, who are some of the hottest tight-bodies on the planet? Or a fashion site devoted to glam-sexy styles? Or variations in between---you decide. Or a 'better sex for bible believing couples' deal where you get the best of both worlds? Whatever you do, research how to make it work first, instead of starting something you actually regret doing, then asking strangers why it isn't working.