I'm sorry that I cannot give you better news.
I'm an FI in the EU myself and from my point of view, obtaining a visa to work as an FI or pilot in an EU country is close to impossible at the moment. If a flight school tells you otherwise, it is likely that they are not telling you the truth.
There are more pilots than jobs in Europe right now and becoming a pilot, in financial terms, is not to be recommended in Europe (my personal opinion, I have a second career besides flying).
However, you, like me, love airplanes and want to fly, no matter what. If I were you (disclaimer: I've never been to Iran and don't know your reality), I would try to become a pilot and fly in your country. Once you have experience and are typed on a heavy jet, you can always apply for other jobs abroad. By then, you'd be a more interesting candidate for the market.
Try to find out how you can maximize your chances of professionally flying in Iran. Despite the situation, it is likely that local airlines appreciate students of certain local flight schools.
Going to Europe at this stage might be a waste of money and time. I would not recommend that.