If you continue with HRT, you're at risk for losing the ability to father children. Your doctor is supposed to explain this to you. The general guideline is about 4-6 months, after that, you're really asking for trouble. That's why you are advised to use a sperm bank!
You need to understand that the primary thinking with HRT is for use in triadic therapy and treatment, under the Standards of Care, for TS clients. Therapy, HRT, SRS all go together as treatment for profound GID. HRT is not generaly used for feminizing the body alone. Impairment of sexual function can be adjusted, sometimes, by adjusting the dosage and adding Viagra.
As you've been advised by others, please speak to your gender therapist. Educated, imformed consent is essential. You really need to understand what you're doing. HRT is serious stuff. It isn't for fun.
I'm TS. I live and work full time, and am planning SRS next year. For me, I need HRT in part, to reduce my sex drive, and since I live full time as a woman, I definitely do not need an unwanted erection! Hormones will help to feminize my appearance which together with makeup and clothing help me to pass. Unless you're planning on living full time, why would you wish to feminize your body? What would you do if you developed sizeable breasts? Is that what you'd like?
You do not have to have SRS. You do not have to do anything! The point of all of this, is to help you to express your gender awareness, and to be happy. It all depends upon what you need in order to find happiness.