The PSA test is unreliable and if your Prostate is much enlarged, this could account entirely or partially for your high PSA. I trust that your GP checked you for a urinary infection as this could also have increased your PSA. However, it could be your PSA test was very high prompting your GP referring you to a urologist. I would suggest that you ascertain the actual number of your PSA test and obtain all details of your histology and any scans done as you are entitled to these and can help you know as you progress, should indeed there be sufficient reason to do these.
If your family were unaware that you were having your situation investigated, I could understand you not wishing to cause them what could be unnecessary concern, however from what you say, it is clear that they are aware and naturally concerned. I suggest you say to them that there is no point speculating - best wait for your appointment with urologist and results of any tests he/she may initiate. It is not an unusual reaction of some men to not wish to involve their families. We know this as sometimes we have a man's partner or family member coming on the forum telling us so and seeking support/information on their behalf. So probably in most cases the partner at least would prefer to be updated on the situation directly or indirectly. Like the man, family members find waiting and uncertainty difficult and this can be compounded if he shuts them out.
Just take one step at a time and cross a bridge only when you come to it because you may not need to cross that bridge but if you do it's usually easier to do so with the support of family (young children could be an exception). We are of course intent on helping the man or his family to the best of our ability, although we are not doctors.