Thanks for the answers. The main problem is that I have an old Mistral Maui with original equipments (it's in a pretty good shape). I have only one hole and a rope "stop" in the masts base and it's hard to use a block (or tackle, I don't now this in English) therefore it's hard to downhaul my sail. Despite of this, I managed to downhaul it pretty hard (with a rope drawer).
So there are three new quiestions:
1, If I downhaul this more, is it possible that my sail would split/broke?
2, If I buy a new mast can I slide it to my old mast base? Here's a pic of it:
3, If I'm not able to fix it just yet, is this rigging will probably cause damage to my new sail?
Thanks again the answers, they already helped a lot!