@sarthina You have developed a nice script. It is quite natural to hit a 'plateau' in your learning where practice just doesn't seem to result in improvement. I was frustrated in my studies of Copperplate as well - so much so that I took a break from it for a few weeks before going back to it.
You have made good progress but if I may be quite frank, I think you are doing it the hard way. Using guidelines makes things very easy during the learning stages. They are useful even if you can write well without them. Also, writing at a larger size makes it much easier to see the structure of your strokes and where you are going wrong.
I think just these two things will result in quicker progress. (You can download the 1/4 inch guidelines I recommend from the group-1 thread.)
I have compiled my best advice on how to form Copperplate letters in the tutorials - please feel free to read through even if you don't want to join it. The 'm' and 'n' are formed by the two basic strokes introduced in the group-2 letters. Practicing these will help. However, I would recommend you start with group-1 so as not to miss out on some of the basic vocabulary and techniques we use in these tutorials. Also, I do see some inconsistency in your 'i' strokes that are wedge shaped due to the taper starting a bit too early.
Engrosser's Script (ES) is a very precisely 'drawn' hand. I see that you are making most of your strokes in one go. While your control is good most of the time, ES requires control all the time. My lessons fall somewhere between the more flowing Copperplate and the very precise ES.
I hope this helps a bit :-)
- Salman