First, I know you already touched on the activity issue and are aware, so I want to preface that this isn't a "be more active" crit so much as it may sound. And second, it bears repeating that you are not shit in any way shape or form. Both your characters' threads lately have all had great responses from you, and there isn't anything I would change characterization-wise at all.
I noticed, though, that with Athos there was talk of struggling with him because you felt you had him "speak" too and that this was in part keeping you from feeling right tagging with him. My advice to you right now is play him anyway. Rewatching the show while not RPing will only take you so far (and may in fact set you back) with that issue, because TV is a visual medium that doesn't involve two people writing back and forth as RP does. TV can get away with saying little to nothing and it's just not going to be feasible to do the same thing in a thread or to compare yourself to that format 100% of the time just as so much that is regularly RPed would never translate to these other mediums. Your best bet is usually going to be to dive in and eventually it will become more comfortable and you'll get your groove. Remember you were accepted for a reason and hang in there!