3weeks PP

Suddenly after a shower I started feeling like my heart is pounding and kind of like I’m breathing heavy but not at the same time I’m not having to take deep breaths or anything like that I have slight back pain but I also BF and the feeding positions are sometimes awkward . I don’t remember feeling like this after my other 2 babies . Any ladies feeling the same or felt the same at some point pp ?? I get bad health anxiety so just looking for peace of mind …