Brother I faced the same issue a month ago but now i am able to write good Pashto and my reading ability has gone from good to excellent.
Here's what i did:
First I watched the YouTube videos on Pashto alphabets - how to pronounce them and how to write them. Then I wrote all of them on a paper and tried to pronounce them without any help. Then I wrote their pronunciation in English, for example Alif, Bey, Pey, Tey etc. The next thing I did was I started reading the pashto book 'Pohana' and my comprehension of the text started to increase within a couple of days. After that I started to write what I read in my own words. I made many mistakes in the beginning in writing certain words but with enough practice for about 2 days I was able to write mistake-free Pashto.
Believe me it's not that difficult as it seems. 1 week of effort will solve your problem.