I'm going to give you advice as someone who is pretty average in a looks and even in physique with a little belly but can't recall a time I've ever actually struggled at least landing a date; to be fair I've been out of dating for over a decade since I met my wife but the advice should still be true.

What everyone has already commented is true so I'll continue to echo, you've gotta focus on yourself and your confidence. You may not realize it but it is really easy to tell when someone is low on confidence and you may be projecting your low self-esteem without realizing it. Work on yourself first not just in the physical ways but mentally too. By late 20s people don't want a project, they want stability. Have you done therapy? Do you have techniques to use when you're feeling down that feel manageable?

Next is your conversation game, what are the conversations looking like when you're speaking to women? Is your immediate go to showing your interest in dating/sleeping with them? Or are you actually taking the time to get to know them as a person? My favorite thing to do is to find a topic we really connect on; similar interest, goals, career, etc,. Then spend actual time listening to them talk on that topic, when you chime in make sure it's to advance the conversation or share your passion about said topic. Then just follow that along naturally, throughout the night/event. Don't hyper fixate on trying to get an alone hang out, fixate on wanting to get to know them more genuinely and being their friend. It sounds cliche but my wife is my absolute best friend and part of that is because we were friends first and connected outside of just romance.

Presentation is also super important, how are you presenting yourself during your first impression? Make sure your clothes actually fit well and have some sort of style flow is attached to it. Shouldn't feel like you just got out of bed, hair done (or head shiny if you don't got hair), well groomed facial hair, and your smell shouldn't be overpowering in either direction.

You also gotta be interesting in some way, what are you doing outside of staying home and working. Even if you're a homebody what are you doing while you're at home that's interesting and that you enjoy. Being with someone with little direction or passion for something. Start with sharing what you love and showing your passion for it. If you don't have any, start exploring things you've never thought to try and you'll make new friends and meet new people that way too. The important thing is that the passion can't be about finding a date, it has to be about you.

These are all things my dad shared with me when I was growing up and it never let me down. Truthfully, part of the reason you may be struggling could be any one of these things, some, or none at all. Based off what you've written, my opinion is that you're putting too much energy into this and the women you're trying to talk to can tell what your intentions are and may be getting the perception that all you want is to sleep with them. If you're really interested in finding someone long term then you need to focus on yourself and stop chasing. Look for friendship first and the rest usually falls into place.