If you can already pull your foreskin back behind the rim (or corona) of the penis head, you do not
have phimosis. It sounds as if you just have a tight foreskin; you can make it loose by doing some stretching exercises. Go to the top of the Men's Health Message Board
and find the sticky headed Stretching To Fix Tight Foreskin (Phimosis)
. Follow those instructions at least once a day for a month and you will be happy with the results.
When i am fully erected i can pull the foreskin over the head but i cant pull it lower
It is ok if your foreskin bunches up behind
the rim of your penis head when you retract it; there is no need to pull it lower than that. Your penis might look "constricted" for a while but gradually the foreskin will loosen and your penis will not look "weird". The foreskin will stay behind the corona when you have sex. Your penis head might feel sensitive for some time but it will become less sensitive if you touch it more (for example in the shower when you retract your foreskin and soap up your penis head to clean it). As you have already discovered, spit is one form of lubrication you can use to help you deal with the sensitivity of the glans when you touch it. You could also use baby oil, hand lotion or even vegetable oil. During sex, the natural lubrication produced in the vagina makes movement easy.
Before putting on a condom, you should always retract your foreskin so that it is behind the rim of your penis head. If you don't, there will be very little pleasure in the stretched frenulum on the under-side of your glans -- and this is where most sexual pleasure comes from.
There is no need to apologise for your ability with English. You have communicated very well!