is my accent going to sound offensive??

so i heard somewhere that if you pronounce the r sound like a normal english r it actually sounds like a swear word?? is that true?? idk im so worried about my accent. also maybe if i talk too fast i dont need to worry about pitch accent right? someone said that on reddit i think. wait is it bad that i cant say the double consonants at all? like i feel like my mouth just freezes up.