Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.

 

In the Name of Allah, Most Gracious, Most Merciful.

 

All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.

 

I am sorry to hear about your condition. Since purification from ritual impurities through bathing and ablution (via water) is a prerequisite for the validity of Prayer in Islam, one is excused only in case of sickness where the use of water is considered as worsening the condition or in cases where water is not available or extremely scarce. In such cases, one ought to resort to dry ablution using clean earth or dust.

 

So, if you are suffering from a health issue and your physician advises you against using water, then you may resort to Tayammum or symbolic (dry ablution) and perform your prayers.

 

Otherwise, you ought to use water for removing both the major and minor ritual impurities as well as other impurities and filth.

 

I am inclined to think that yours is related to some phobia you have developed, and you should able to overcome the same by seeking the help of a professional counselor.

 

Allah Almighty knows best.