Aside from the advice of seeking the help of a medical professional, the Kabbalist Rabbi Yehuda Patiya writes at great length on this subject, as well as the remedy in his popular sefer Minhat Yehuda Parshat Miketz letter 47. The Pshat of his remedy is to say Kriat Shema Al HaMita with the utmost kavvanah. He also gives another small prayer to banish spirits from the room. Which is to say טמא טמא ברח לך מכאן tamei tamei barakh lakh m'cahn three times. I once asked Rav Kaduri ZTz"L about this. He said that it needs to be said in the Hebrew. I also asked him why Rav Patyah brought it, if Kriat Shema works. He said that it is often hard for people to concentrate as is needed, and thus if one starts to have bad dreams, then one should resort to this.
If it is a spiritual problem, than that should fix it immediately. As it says in the sefer, once one tells the sheidim to leave, they have to leave. If this does not work immediately it should be assumed to be a medical/psychological issue, and as the others have stated medical advice should be sought. Even if this does resolve the immediate issue, it would still be good advice to seek out a good therapist. B"H in this day and age there are Orthodox Jewish therapists and psychiatrists so one need not worry over the issues that initially set much of the Torah world against psychology.
No "mekubal" will be able to do for you more than the advice I have given above. Any "mekubal" that requires monetary reimbursement for their services is simply not to be trusted. For a more comprehensive grasp on precisely what is valid, and what is not see Rabbi Yaakov Hillel's book Faith and Folly. A good portion of it can be read there online.