I started at a very young age and it's like that world has totally no connection with the real world. There is just a primal need that knows nothing about social rules and morals. Therapy certainly helps, but it's important to be on birth control pills from the physician. I don't tell my physician my psychiatric problems as physicians aren't usually trained in psychology and mostly aren't so interested either. I think it would help to tell your therapist and try to get your alter aware of real life while taking the birth control. The alter may not even realize that unprotected sex could mean having a baby to raise, and getting pregnant is as easy as catching a cold.

That would be my advice from experience. It turned out to be stage for me and I got through it and co-conscious in about a year. Also there is such a thing as addiction to sex, where that part of you or all of you is seeking to relieve emotional pain by the excitement and good feelings of sex even tho dangerous and temporary. I know this is a sensitive subject and I don't want to give you wrong advice, but that is what worked for me.