I have never used the Master Protection Ritual. I read mostly ‘old books’ xD
The LBRP is a great ritual. It can be modified and used for all sorts of different things. Using it for defense, my suggestion to you would be to really focus on the pentagrams, the invocation of the angelic archetypes, and really get a feel for energy that you are moving. One time a day is good enough. If you want, you can do it it two times a day: once in the morning and once before bed.
To protect yourself and others with the ritual, don’t just anoint the halls with the pentagram. When you are in the ritual, drawing the pentagrams, expand them. See them shielding yourself, your house, your property, those close to you. Keep them all in the protective circle you are creating. Feel the energies realign around them and know that they are safe within the sphere.
As a preamble you could do the Qabalistic Cross as a sort of invocation of Omnipotence before and in closing after. As is traditionally taught. It will give the ritual an extra oomph in power.
Once you have preformed the LBRP, you could do the Analysis of the Keyword, or LVX. Its another ritual taught in the Golden Dawn, but it draws down divine power potently. Instead of your typical white light, you should use Red and project the properties of the Archangel Michael into the light. When you command the light to descend, you bringing Michael crashing down into your earthly sphere of reality, drawing forth his protective, cleansing powers, to saturate you and those around you, your property, etc. Be sure to see and feel every atom get anointed with the angels power.
So the order goes:
Qabalistic Cross, LBRP, LVX, Qabalistic Cross.
You can do it once or twice daily.
But if that all is complicated, I admit it might be for a beginner, you can just stick with the LBRP. Just project the pentacles out into a space, via visualization, so that it protects everything important to you as a catch all.
Other than that C.Wilson has some good points.
Believe in yourself, and don’t shoot yourself in the foot by doubting yourself or your effectiveness. You are fighting magic with magic. If you are in this serious of a situation, you don’t have the luxury to doubt yourself. Your curser surely has self-confidence, and you don’t doubt their abilities? A lot of people give their ‘enemy’ way too much credit in terms of power. <-- Just an FYI there. As I said before, doubt, worry and anxiety bring their own energetic values to your workings, and they don’t effect them in a positive way.
You are just as worthy to wield magic as anybody else.