ISO 3200 OUCH!
That is a very high ISO for that range of camera - infact its way too high and you can see the result its had in your shots. A lot of noise and a soft result with details sadly lacking. I know lighting for this kind of macro work is no easy thing, but if your forced to work with an ISO that high its going to heavily impact your work.
If you don't have a speedlite flash try the macro flash snoot suggestion in this thread here:
Juza Nature Photography Forum • View topic - Macro techniques, tips and problem solving
that would let you get some usable light from your popup flash to help you use a lower ISO.
Also there is another trick you can learn - if you put the lens on the camera and select the desired aperture you want to use (eg f13) and then press and hold the depth of field preview button. Then whilst still pressing that button turn the camera's power off - the result is that the lens aperture blades will remain closed and thus when you remove the lens and reverse mount it your aperture is closed down and thus you will have more depth of field to play with. Sadly though you will also have just got a verydark image in the viewfinder to focus with = to counter you can use an LED torch with a single bulb on a flexi arm to illuminate the subject when focusing. Of course this is all rather hard if your holding the lens to the camera as well as working with a living subject so you would have to experiment a bit toget a working setup.
Your certianly getting a good magnification there so keep at it and experiment with the setup
I would also suggest that in the furture you limit your uploaded images to 1000pixels on the longest side at most (I think we even have it in the rules around here that 800 is the max you should use) and then if you want to show a larger version have a direct link to it in the post. This means that people on slower connections can still use the site without problems