I have experienced love in dreams in some form. There will be that person, the embodiment of everything you want, your dream girl or guy as it were and it will be spectacular. However real the experience will feel, once you wake up, or attain lucidity you should realize that it is all a construction of your own mind.

Sure the emotions will feel real enough, but the fact is that it is not. Real relationships, with other individuals might not be perfect, they take work, but overall they are far more rewarding. It is not love you have with a dream character, it is masturbatory (narcissistic even) to act as if it were.

I don't know if professional help is in order, I think you just need to acknowledge that it is not real, and find something else to occupy your mind. Hang out with real people, immerse yourself in the real relationships you have, see the difference, and forget about your fake one.

Be glad that you have the ability to become lucid, and incubate and bring out specific characters (and I can only assume locations and other stuff). Everyone hits dry periods, it will come back, but hopefully by then you will be over this.