You really need to explain to us in substantial detail how
you are doing this stretching, and particularly, by reference to the techniques we have described here. Unless we know that you are doing something that is effective, that you are stretching the right part, we cannot hope to comment on why it may or may not be effective.
It would also be useful to know your age, particularly in respect of your second question. One would presume
that you refer to putting on a condom in order to have intercourse with your girlfriend, it that the case? (Not such a silly question as it sounds - some people have different agenda!)
If that is indeed the case, then unless you are saying it is in some way uncomfortable (and it would have to be very
uncomfortable to cause such problems), then I would have to say that the issue is not with the phimosis, but with the relationship and/ or situation with your girlfriend. The two usual "mockers
" are guilt and fear of pregnancy - and the latter is usually quite justified.