I'm going to stand my ground in an argument about who I choose to be friends with
What happened? Is someone questioning your friendship with others?
I'm going to stand my ground, but at the same time I have a lot of doubts about how good they are
It's good to stand up for what you hold to be true. This will help you to be taken more seriously by others.
I'm going to do that, but I know I'm going to regret it.
You're the only one who can decide if you're going to do something and may regret it later. What I would do is to make a pros and cons list so that I would know if doing something is worth it or not. If it is not worth it, then you should just go and do something that is better in the long run.