I've been meaning to write a blog post about this for some time now and have been doing a lot of research on the topic, but from what I've gathered so far, watching porn and masturbation on a consistent basis, where it is pretty much an addiction, is highly likely to have a negative effect on your ability to attract women.
Firstly, when you ejaculate, testosterone is lowered, you lose some of your sex drive and your body is depleted of energy.
Testosterone is the hormone that makes us men, gives us manly like characteristics and makes us want to stick our penis into a vagina. When we are releasing that testosterone through masturbation, then we are losing our motivation to seek out and attract women in which we can ejaculate through sexual intercourse.
Ejaculation through masturbation is a reinforcing habit, an addiction. It feels good when we ejaculate and thus it creates a positive reinforcement to whatever it is that made us ejaculate in the first place. Thus when we masturbate on a regular basis than a habit of masturbation forms, rather than a habit of seeking out women to have intercourse with.
In conclusion, if you masturbate to porn in moderation, say once a week, than it probably isn't much of an issue for you. If you masturbate at least every day then it's clear you've formed a habit of masturbating and is quite possibly affecting your ability to attract women.
Edit: I got carried away discussing masturbation that I forgot to apply it to the OP's original post -
Watching porn and masturbating to it reinforces your attraction to the porn star look and will cause you to become less attracted to more average looking women like your thin small breasted ex. Perhaps try quitting porn for a few weeks and then see if you still have an attraction to your ex?