I think that if you really believe that you have a karmic lesson to learn which requires you to have no good luck during that particular year, then you are very likely to unknowingly attract the very factors into your life which would greatly increase the chances of bad luck happening.
This is called a negative self fulfilling prophecy.
Essentially through your strongest and most regularly held beliefs about the world wanting to punish you endlessly for unknown reasons, which often also manifests in your mind as you seeing demons everywhere, you are helping to attract more bad luck and unhappiness into your life.
This is called the downward spiral of depression, where the symptoms of your depression are used by your mind as evidence that the world is and always will be against you.
Then your mind conveniently ignores anything which happens to you which is good luck, because to accept that something good has happened to disagrees with your theory that nothing good ever happens to you, or that only bad things happen to you.
Also you are overlooking something very important about the dangers of using numerology to predict your future.
Even if your personal year is 3 and numerology is telling you that you have an increased probability of receiving a gift (good), getting a new girlfriend (good) someone doing something against you (bad) and you going into hospital (bad), there are practical things which you can do to significantly reduce the chances of the bad things happening, as well as reasonable things you can do to increase the chances of the good things happening.
If you make everyone around you uncomfortable and are always complaining, then you are less likely to be given a gift. If you stay alone in your home and do not go out and meet girls, then you are unlikely to get a new girlfriend. Even if numerology tells you that both things are likely to happen, if you do not do the things which will help to make these things happen, they usually will not.
To reduce the chances of someone doing something against you be more careful with whom you socialize or share your secrets. Find a workable balance for you between being careful without seeing everything which people do as as a personal attack, or something which is against you. If you cannot trust someone sometime forget about having any close human relationships, as close human relationships are built upon trust (and love).
To reduce the chances of going into hospital do not do silly or dangerous things which could lead to you being hospitalized because of an accident, take sensible safety precautions, take better care of your health, and go to your doctor if you experience any unexplained symptoms which persist for more than three consecutive days and do not respond to home or over the counter remedies.
Numerology can sometimes tell you about the probability of a future event (good or bad) happening, but it is mainly what you do in the present moment to help yourself which largely determines what your future will turn out to be.