I was praying Fajr and I was very tired, I remember that I was in my second rak'ah and sat for the Tashahhud, however shortly after I went to sleep sitting down. After i woke up I don't remember if i finished my Salah or not, is this considered doubt after I'badah which I should ignore?

Ustadh AbdulAziz al-Haqqan

No, you should repeat the salah because certainty is not removed by doubt, and you are doubting whether you finished the salah or not, therefore we go back to certainty which is not finishing the salah.