Best type of therapy for low sexual self-esteem?

Hi,

I'm in my 40s now, but in my teens and twenties I had crushingly low self esteem and believed I was very ugly and fundamentally undesirable (thankfully I now realise this is not true). That meant that I had very limited sexual experiences, and I feel like this means I did not have a 'normal' sexual development. I feel like I missed out on a lot of the normal growing up, experimenting, and enjoyment that most people experience.

Although generally I feel much better about myself these days, that idea of being very unattractive and unwantable sticks with me in some core part of my sense of self. It causes very real problems in my current relationship, with a beautiful partner who I love very much, and who loves me and I know finds me attractive. My partner had what is a pretty normal, active sex life in the past, but I feel a lot of pain and jealousy when I think of their past experiences, and I'm pretty sure that's because of my own perceived lack of experience in the past, and how I felt about myself. It's the biggest issues in our relationship and I really want to deal with it, come to terms with that period of my life, and if possible move beyond it.

I'm looking for therapists but am lost as to what the best therapeutic approach might be. I'm leaning towards CBT but am not sure if this is appropriate in this case. Can anyone share ideas or experiences in this area please?

Thanks!
Kato