Hey Marc,
A couple of questions for you based on this new info:
A) How are you usually connecting with these potential partners? Is it mostly via apps? Bars? Social activities? Some other way?
B) At what point in the connection process, whatever form that takes, are you usually laying out the fact you've not got lots of experience?
I think it is likely that connecting through hook-up apps (such as GayXchange, Grindr, Planet Romeo, etc.) may have issues for you because I could see Grindr type hook ups not being the most congenial way to get yourself out there. Most people use these to get sex, right now. It would be easy online to dismiss someone who notes in their profile that they are inexperienced - if you happen to do that.
Face-to-face in a bar would let potential bed pals at least get a look at you, chat you up a bit deeper and see how you are as a person. There's a bit less "quick fuck" attitude in a bar (less, not none) so chatting someone up while having a refreshing beverage can easily bridge the potential gap between "no experience = no go" and "Yeah, this might be fun". It would be the interactions between you and the potential bed buddy that would make the chance of getting that experience you need/want. As long as you're not super tense at the idea of that actually happening.
If bars are not a potential connecting venue for you - such as there are actually none in your neighbourhood, you are just not comfortable in such a place or for any other reason - what you might want to try is to get involved in a third possible venue: social gay groups.
Meet other gay guys on a level that ISN'T about hooking up or getting sex or finding Mr Right or Mr Right Now but is based on a shared external interest. Hunt up and join a group of gay model train enthusiasts, a gay cooking club, gay choir, gay sports league, gay politics, gay whatever. Whatever you do already (or would like to get into) is a good type of group to get in with.
You can then meet up with other gay guys who already share your interest and get to know them (and they you) on a more personal level long before the idea of sex enters the picture. You'll likely also meet lots of people who are not going to be compatible bed buddy material BUT that's fine too. They can be friends and if you socialize with some outside the one activity, you may meet friends of theirs and THEY may be the guy who's open to taking you under his wing. Show you the ropes, get you that experience badge.
Second benefit: this is going to be a much more "organic" way of meeting possible friends and, perhaps Friend With Benefits or even actual BoyFriend. It's like the way a huge number of people make new friends and eventually meet their best bud who then in turn becomes a boyfriend. This more organic process should help you build up your confidence. You'll hardly even notice that you're opening up and becoming more confident because you're just hanging with new friends.
So that's my take on things, based on what you've included above. I'm not claiming these are The Golden Steps to absolute effective end results, just some ideas to ponder. They may not apply for you at all. But they're at least a start.
Hopefully, others will jump in with different takes on what you've posted so you have a wider set of viewpoints to ponder.
I hope you can get passed this roadblock and find much joyful experiences soon.