Well, suggestion for citrulline+ beetroot was given couple of weeks ago when your libido went up a bit, but erection quality was not great so thats were these two can do a great job. Now, in meantime things went bit sideways. E2 is a main contributor to both libido and erection quality- and your E2 is all over the place, and probably rest of your hormones as well- so thats first thing to sort out.
As for beetroot- I buy them at grocerie shop, weekly supply cost me around 2-3 $.