To let you know this is very common - so much so there is advice from mental health individuals on how to handle this.
Here is an answer from a professional on this:
You may be surprised to know that what you are experiencing with your therapist isn’t uncommon. In fact, what you are likely experiencing is a phenomenon known as “erotic transference,” which is when a person experiences feelings of love or fantasies of a sexual or sensual nature about his or her therapist.
It is easy to see why you might have developed these feelings. Your therapist may embody many, if not all, of the qualities you may desire in an ideal mate. The therapist is accepting, attentive, kind, and nonjudgmental and, for at least an hour every week, fully engaged with you. One of the problems with this sort of situation is that you are falling for an image you have of the therapist, not for who the therapist actually is. You know very little about him, and you have used your imagination to fill in the rest. You have created a fantasy of sorts of your unmet needs and have imagined that the therapist is that person.
It is not “nuts” to share this with your therapist—in fact, it can actually become a significant turning point in your relationship with him. In many cases, this deepens the therapeutic work and allows you to process things on a much deeper level. It will take courage and trust for you to share this with your therapist, but taking that kind of risk in therapy is necessary for growth.
There are a number of ways in which your therapist might respond. Ideally, he will be able to help you recognize what is going on beneath the “crush” in order to get to the deeper material. Many times, therapists in this situation are able to work with the person in therapy and generate meaningful transformation.
Of course, if he is not comfortable with continuing work with you, he may refer you to another therapist. Unfortunately, there is no way I can offer a definitive answer as to how he might respond.
What he ought not do is share that he has similar feelings or act on any feelings. As you mentioned, there are rules in every state that forbid romantic relationships between therapists and the people they help for a certain time period after termination of the therapy (it depends on your state). Regardless of state regulations, the ethics code of the American Counseling Association (2014) specifies that there must be a five-year period between the end of the counseling relationship and the start of a sexual or romantic relationship. It would be highly inappropriate, unprofessional, and, yes, illegal for your therapist to do anything other than work with you through this or refer you to someone else.
I hope you can navigate this with grace and recognize that what you feel can be and often is a part of the therapeutic relationship. In fact, I can’t think of one therapist I know who hasn’t experienced this, so please don’t feel as though you are an anomaly. It’s very normal, but the important thing is how you handle it; be honest, sit with his response, and most of all, treat yourself with the deepest level of care and compassion you can muster."