Poland is definitely not one of the greatest countries to be in with regard to this kind of situation. What your parents are doing is indeed terrible, and if this experience could tell you anything, is that human beings are absolutely not as bound by blood as idioms tend to portray.
What I recommend you do is backpedal. There sadly is nothing of benefit that could come from you continuing to hold this position to your parents, considering they would continue to coerce you with the harmful things they are doing.
Try and work and grow toward becoming independent without having to rely on your parents, whether that means getting a job, moving out, being able to possibly move out to another country as you possibly progress, and so on. The situation you are in is undoubtedly difficult and hard, but it is not the end of the world.
Your light would have to be the possibility to break free from the control of your parents, and that's exactly what you have to work with. As bad as it may sound, you did get forced back into the closet and you have to play your cards right, considering this is a matter of you essentially surviving.
Do whatever keeps you sane and try to improve your relationship with them for as long as you have to be under their control. You could go as far as saying that you only had some 'stupid thought that is now gone', that you had a 'revelation', some kind of 'message from God' or whatever else that could bring their image of you back to a positive one.
As they appear to be fanatically religious, based on what you mentioned, you could most certainly say you just recently had a dream that 'brought you to light' and they'd absolutely buy it. It might help you defuse the situation to some extent and regain their trust, which can pave the way to you moving out to study or work or get in a position that frees you.
Your own thoughts and ideas can be kept to yourself until you manage to move on from their control. Keep in mind that the situation you are in is not your fault; those are simply narcissistic and fanatical parents—there sadly are plenty and enough of them in the world.
They were faced with a choice of supporting their child and living a healthy life together, or spending their last days in a nursing home, alone, all because some metaphysical spirit is telling them to. They chose the latter, and the only loss is theirs, I can promise you that. Stay strong.