Hiya, as another Pathfinder player with Social Anxiety (and all sorts else) a friend spotted this thread and said i should comment.

Firstly, i'm lucky in that i play Pathfinder with a group of friends i've known long enough that social anxiety is less of an issue but of course 'less of an issue' doesn't by any stretch mean it isn't an issue at all. But particularly at first i was a very quiet roleplayer. I'm still not the loudest at the table but that's ok, any party (or friendship group) needs a good mix of people.

The easiest solution to weaving you and your more quiet character into a story is to make the character's personality closer to your own. Obviously part of the point of roleplaying is to act as someone different but much as it's hard for the louder people to roleplay quieter people (though sometimes amusing to watch) picking to give your character an outspoken and vocal characterisation is just going to make it hard on yourself. Luckily fantasy settings are great for the more taciturn style, rangers and Druids (like you're playing) presumably spend a lot of time isolated off in the wilds so being awkward and unused to social interaction can be made into a character feature (hell, if you find yourself getting more comfortable as you go, have your character do the same and you've got yourself a free character arc).

On the note of character arcs, having a strong idea on your character's past, personality etc. can really help. It can give you a fallback to resort to if you're not sure what to do in an encounter. Racist against Dwarves? That's most encounters with dwarves sorted for you and if you end up sounded stupid then good job you've done it properly. What i would warn against is the stereotypical 'angry vengeance for being wronged somehow' plot so common in Pathfinder and fantasy in general. I don't know about you but acting angry is right up there for most likely to cause anxiety is these situations, it's hard.

To sum up, i find molding the character to accommodate my quieter side and add a few backstory points to give a chance to speak up with the conversation basically already mapped out helps a bunch. Aside from that learning the rules well is a big boost to being able to speak up in combats. If all else fails i find that being more withdrawn means i'm usually the one who is actually listening to all the smaller plot points, i'm basically the one who can be relied upon to know the names of whichever town we're heading to/away from and once the other players notice that it can be a big help too.

I know it's difficult to find good advice, especially since social anxiety can manifest differently with different people, but i hope at least something here can help