Is my ablution and prayer valid without the conscious awareness of intention, given that I suffer from severe obsessive-compulsive disorder?

What you are doing by ignoring the whispers (waswas) concerning the intention (niyyah) and proceeding with the prayer is correct. The matter of intention is simple: as long as you know what you want to do and you intend it, then you have made the intention for it. Your claim that you do not "feel" the intention is a whisper. How can you perform ablution and prepare for prayer, and then claim that you do not "feel" the intention? Continue striving against your self until you rid yourself of these whispers.