My career started very similar to yours. I did not have a CS degree when I started work. I was in my early 20's, and the only female on a team of older, somewhat hostile developers. I felt out of place from my first day. Some of the things I did to survive -
I was quiet and humble. I never assumed that my point of view was right until I was absolutely sure.
I got a mentor at my company that I was comfortable with and could ask questions without feeling stupid.
I never let myself be excluded from development meetings. Even if you're not working on the task that the meeting is about, don't get left out. The more knowledge you have about the project, the better your position will be in the future when your coworkers move on to other projects. If the other developers are too busy to work on something, you will be able to step in and take over.
Find your niche. Don't try to be an expert on everything. If you are really good at something that other people won't touch, you will become the "go to" person for that skill and you will become invaluable.
Take advantage if your company offers tuition reimbursement or training classes. This is how I eventually ended up with a CS degree.
And remember - everyone, no matter how much experience they have, is capable of making dumb mistakes and being wrong. There is a lot of code written by senior staff that just plain sucks. They may turn on you because you're new, but in my experience they'll also turn on each other in a heartbeat. So don't take it too seriously if someone talks down to you.
Good luck!