Hi Little bear,
sorry things have taken a back step for you, anxiety is crippling when it takes over your life, just remember though its understandable and grief takes alot of time and when its combined with PTSD i guess its even more complicated. I don't know about the medication but i do know you build a tolerance to certain medications when you have been on them for a period of time. Sometimes we don't always know why things change and we seem worse, the important thing is dealing with it, maybe a medication review would be good? What other ways do you use to manage your anxiety beside medication? maybe try some of those strategies to try and ease the burden a little.
You said its the month anniversary, often anniversaries can be a triggering and anxiety provoking time, maybe that could be playing a part in the heightened anxiety and fear you are feeling. Just some ideas, i hope things improve soon for you.
Sazza