I do not think badly of you at all for having those feelings. I think it is completely normal.
I have some single friends, some married w/o kids friends, and some married with kids friends. Having DD has affected my relationship with all of those friends in different ways. We do not have any family nearby and, so far, do not have many options in terms of babysitters, so that makes us go out in the evenings much less frequently than we would have before. It has also limited the places that we can go to with friends. We live in a small town with limited "going out" options and two of our friends' favorite places to eat dinner or watch games together are technically bars, which means that DD is not allowed to go in. It is a bummer each time we have to say that we are not going to join our friends because DD isn't allowed.
Another of my favorite activities is running road races. It is something that H and I did often together, but something that is much more difficult with DD. Jogging strollers are not allowed in most of the races here, so in order to run together, we need to find someone who can babysit from like 5AM-noon on a Saturday. For some reason, the local high school girls don't like to be at our house at 5AM on Saturday? Odd...
Do you have anyone who DS could stay with for one weekend per month or even every other month so that you could to LARP once in a while? I don't know if it is something where you need to be there every time or if you can just go sometimes? My mom or MIL would love to do that with DD if they lived closer.
I am not doing a good job of this, but, it might also be time to make some new friends. I wish I knew how to do that, it sounds like Mommy and Me is a good opportunity since you SAH. In my community there are a lot of other activities similar to that, you may have access to a lot more than you even realize yet.
Anyway, no, I would never change having DD, but yes, things are totally different.