Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
1) Scholars state that the Du’a made after drinking some Zam Zam water is hoped to be responded to. Ahmad, Al Hakim and Al Daraqutni reported from Ibn Abbas that the Prophet (Sallallahu Alaihi wa Sallam) said: "Zam Zam water is (good) for what it is drunk for." Ibn Al Jawzy reported in his book Al Adhkiya that Sufyan Ibn Uyaynah was asked about the authenticity of the above Hadith, he said: "It is an authentic Hadith.” Therefore, you can, dear brother, make Du’a, drink of Zam Zam water with the intention of being cured of what you mentioned or of anything else.
2) We do not know anything which, if done, makes the person see the Prophet (Sallallahu Alaihi wa Sallam) in his dream. But the more the person is pious and the more he follows the Sunnah, there is a greater possibility for him to see the Prophet (Sallallahu Alaihi wa Sallam). Anyway, seeing the Prophet (Sallallahu Alaihi wa Sallam) is a favor that Allah bestows on whom He wishes. But not seeing him does not mean that the person is not good or not pious.
3) Having difficulty to lower one’s gaze is usually a result of some weakness in one’s faith. So, anyone who feels such a thing should endeavour to strengthen his faith by doing the following:
1) Adhering to the good environment such as attending Dhikr circles, reading Qur'an, and praying in congregation.
2) Making one’s ideal the good pious people.
3) Staying away from dissolute and bad people.
4) Busying oneself with matters to benifit him in the next life..
5) Not having too much hope in this life.
6) Limiting one’s expenditure in food and clothing to the minimum necessary.
7) Making Du’a to remain steadfast and pious.
Allah knows best.