Shad -
You can take a Sears Roebuck catalogue. Place its spine on the table. Let it fall open to any page by chance. Whatever you find on that page, be it corsets or harrows, perfume atomizers or wall safes...someone, somewhere, is sexually aroused by whatever is on that page.
Being aroused by things is normal and healthy. Even harrows and wall safes. Heterosexual men are commonly aroused by women's breasts, women's hips, their hair, their legs...whatever. This could be because of a longing for mother, or their hidden/forbidden aspect or something else. It doesn't matter. The thing is that some people might regard arousal by a wall safe as unhealthy whereas arousal by women's breasts is okay.
No.
What is not okay is when it becomes an obsession. You seem to have a size fetish and fantasies about size. There is nothing wrong with this, at least to my way of thinking, as long as it does not interfere with living your life and otherwise normal physical/emotional development. Where it might be a problem is if you did not get involved with someone who was otherwise right for you because her breasts were too small...or his feet...or whatever other permutation of gender and physical characteristics happens to be involved.
The thing, Shad, is that we often do outgrow our fantasies. When a fantasy becomes a reality, it is no longer a fantasy, thus when you finally do have a relationship with those big breasts or those big feet, it has happened. Then it must be replaced by a new fantasy. When the subsequent fantasy is directed toward ever bigger things, there might be a problem, but this generally doesn't happen. What you generally find is that those big breasts, feet or whatever are just that and nothing more and that just isn't enough to sustain a healthy relationship, even if they can sustain healthy fantasies, in addition to carrying burdens in reality that never seem to find their way into the fantasies. Howmany men fantasize about having a larger penis? From what I gather, a lot. How many of them fantasize about sitting ontheir balls, as so often happens to me? I'll bet none of those fantasies include that. The fantasies are all about appearances and glamor and it is this unrealistic aspect that is their value.
Just keep your perspective. I know, easier said than done. It matters not whether you are straight, gay, bisexual or neuter, but we all have our fantasies and frequently they are what keep us going.