You could say I’m questioning about being poly, but I also have a lot of anxiety. What are ways for me to be more accepting and less worried that potential partners will find someone better than me if I do get into a poly relationship or open relationship?
The first step is to get help for your anxiety! You know that your anxiety is preventing you from living your best life, and knowing is half the battle. (Well, at least the first step in the battle.) If you aren’t already, try talking to a therapist about the anxiety. If that’s not a step you’re ready to take, consider ordering some books or workbooks on anxiety-management techniques like DBT and CBT. There are also lots of apps, wearable tech gizmos, and websites to help you manage and reduce anxiety. You can find a bunch of resources on my page here.
As for anxiety specifically about polyamorous partners finding someone “better than you” - here I go again with the cliches - knowledge is power. Learning about polyamory, how it works, how other people manage those fears, and how to mitigate those, can really help. Do some research on polyamory - you can start with the books and websites listed here! There is some great advice already out there that might help you find your footing.
Also, and I know that it’s nearly impossible to reason someone out of an anxiety, but here’s my perspective on this anyway: in my experience, dating polyamorously actually reduces rather than increases the risk of your partners leaving you for “someone better.” With monogamy, if your partner meets someone they want to date, someone they find interesting, someone who offers the potential of an experience they haven’t had with you - they need to leave you, or cheat on you, in order to find that. With polyamory, your relationship with each partner is secure from that specific threat. They don’t need to torpedo your relationship to pursue someone else they’re interested in.
That’s not to say that poly people don’t get left, or broken up with, and it does happen that someone dating polyamorously decides to “go mono” with one of their partners and leaves their other partners - but polyamory does not mean that people are dating you while dating around in pursuit of someone “better.” It’s not about finding someone “better” than you. All people are different! You offer unique things emotionally, intellectually, sexually, etc. and so does everyone else! Coming back around to my first point, working on self esteem and security within yourself will be key to addressing this issue.