Upper strut mounts and/or spring seats are frequently reported to fail at about the mileage you have. Need to remove the strut to replace them. Need to contrive to maintain front end alignment or have realignment done afterward. The struts themselves may or may not be too worn for your ride comfort, good handling and overall driving satisfaction. If replacing struts I would do both sides. If replacing mounts or spring seats I don't see a need to do both sides unless both are bad.

There are many previous posts on this issue (and choice of strut types and brands) and there's a web site that illustrates the procedure (probably referred to in some earlier posts).