Assalam O Alaikum Wa Rahmatullahi Wa Barakatuh Sister,
There is not enough detail but if I understand it right, you had some evil thought while praying. Since you did not act upon it, you will not be held accountable for what crosses your mind.
Al-Bukhaari (6491) and Muslim (131) narrated from Ibn ‘Abbaas (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said, relating from his Lord, may He be glorified and exalted:
“Allah decreed good deeds and bad deeds, then He explained that. Whoever thinks of doing a good deed then does not do it, Allah will write it down as one complete good deed. If he thinks of doing a good deed and then does it, Allah [may He be glorified and exalted] will write it down between ten and seven hundred fold, or many more. If he thinks of doing a bad deed then he does not do it, Allah will write it down as one complete good deed, and if he thinks of it then does it, Allah will write it down as one bad deed.”
Al-Bukhaari (5269) and Muslim (127) also narrated from Abu Hurayrah (may Allah be pleased with him), that the Prophet (blessings and peace of Allah be upon him) said:
”Allah, may He be glorified and exalted, will forgive my ummah for whatever crosses their minds so long as they do not act upon it or speak of it.”
And only Allah knows the best!
Ma’aSalaam