How Can I Liberate Myself from Guilt & Shame & Enjoy Sex with a Woman?

Dear Dr. Betty,
I don't feel comfortable with myself because I am 30 and never had sex. Not even a kiss, not even a relationship with anyone, never been touched by anyone, never touched anyone. Nothing. Never.
Since I was 13, I am perfectly aware of my being lesbian, and I spent a long time feeling guilty about it. I've felt wrong for long. More precisely, I have been feeling guilty, shameful and all that bad stuff about sexuality. About being sexual, you know?