Advice on how to feel more confident in myself/my relationship please! Help, I'm so lost, scared and confused.

*NP: abbreviation for nesting partner (partner that shares a home with me)

For context: me (23yo) and my nesting partner (24yo) started dating as a enm couple in 2020, but barely acted on it till 2023. We've been living together since 2021. I'm sure I want enm but not 100% sure about polyamory.

Ever since 2021 I've been having doubts about being asexual (or am I just sexually traumatized?) My partner has a very high sex drive (sex everyday, sometimes multiple times a day). This discrepancy has been the major issue in our relationship. I feel mostly sex-neutral/positive when it comes to my NP, but sex-repulsed by others. I still can't give them the frequency and excitement about sex that they crave.

We both want very different things from enm/poly. I enjoy casual hookups/kissing in parties and casual flirting. My NP wants to build relationships and have regular sexual partners with the possibility of turning into a serious relationship.

I'm having trouble dealing with the jealousy when it comes to their needs. I know I'm not enough when it comes to their sexual needs and it kills me from the inside thinking about them finding a regular partner that can do that for them.

After sitting with it I came to realize I've gained most of my self-worth through external sexual validation and I've used sex mainly to feel secure in relationships (if I'm pleasing, then I won't be abandoned). Rn, I know I can't please and it feels like I will be abandoned (even tho NP actions and words say the opposite, I catch myself scared, waiting for the day they'll get tired and leave).

My question is: how to feel secure in my relationship with NP? How to stop being terrified of NP choosing to spend more of their time with someone else bc I can't give them enough sex? Of them finding a more sexually compatible partner and start prioritizing their relationship over ours?

I know I still have much internal labor to do to make this work. All I'm asking is for advice on how to feel more confident in myself and in my relationship. For resources. Similar experiences. More info on asexuality and enm/polyamory. I'm already so confused about my (lack of) sexuality, this makes me feel extra confused.

Thank you for your time! I hope this isn't too confusing.