salam.pls,i have problem in pronouncing arabic letter Ra.what shall i do bcos i'm nervous about my prayer especially in takbirat ihram and fatiha

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

If you are not able to pronounce the letter (Raa') or any other letter for a defect in your tongue and the like, then your prayer is valid as well as the prayer of those whom you lead in prayer of those who are like you unable to pronounce some letters.

However, it is not permissible for you to lead in prayer those who recite Quran well and pronounce letters properly. For more benefit, kindly refer to the Fatwa 123119.

Allaah Knows best.