I'm a native Persian speaker and I've been learning English since I was 11.
Of course in the first years of learning, I actually had a lot of mistakes in choosing methods that I will never repeat in learning a third.
One of these mistake is that I didn't start to learn English through an L2 to L2 method (Internet was not as common as it is nowadays in Iran and so I wasn't aware as I am know. Teachers speak in Persian while they are teaching English. There are a lot of factors that limit the chance of a second language learner expose himself to a simulated environment of second language)
Now the conditions are different a bit and as an Engineering student, I try to expose my self to English as much as possible through chatting with native people, watching satellite English channels, reading news and books in English, etc.
It was really a hard job to accommodate with the new situations. For example when I just started to watch English TV series, it was apparent that I take a while in my mind to understand in Persian (It is still a problem but I'm trying to handle it)
Anyway, my reading skills are pretty good and I have participated in a translating job interview which shows that I'm qualified to work for them (the work involves with translating academic Persian papers to English to help the ones that want to publish their research results in English journals and sometimes vice versa)
But I'm a bit worried. Will that job affect my effort of understanding English in English? (I'm planning to participate in TOEFL exam in the future, I'm very good in understanding that kind of stuff but I need to work to accelerate my pace to understand real life English. I'm still weak in understanding every word of a native in different accents)
If it will affect my L2-comprehension, then what can I do to mitigate this effect?