Sajda-e-Sahw

Q: For Asr Prayer, if I mistakenly performed 5 rakaats instead of 4 rakaats, how do I correct the prayer? Do I need to perform Sajdah Sahw or repeat the salaah?

Q:

1. If I am praying 4 rakah salah and in the last rakah I doubted whether I prayed 4 or 5 rakah... as there is no 5 rakahs so I base myself on 4 rakahs and complete my prayer without doing sajda e sahw...is my prayer is valid?

2. Do I have to do sajda e sahw in this situation?

Q: How do I perform sadjah sahw?

Q: If a person fulfilled all his past sajdah sahw as a single sajdah instead of 2 sajdas due to ignorance of it, will qaza have to be made? 

Q:

1. If in namaz, just before saying salaam, either my head is on the right side or left side, if I unintentionally say Allahu akbar and then say salaam, is my namaz valid?

2. If I need to do sajda-e-sahw in this situation, how do I do it? I have alraedy recited attahiyyat, durood and dua and then before salaam I unintentionaly did this.

Q: I forgot to recite a surah after reciting surah faatihah in the last rakah of witr salaah. I also forgot to recite dua qunoot in it. Will it be sufficient for me to perform sajdah sahw?

Q: We missed the surah in salaah. What should we do?

Q: I have a medical condition that has me in continuous pain. At times, due to the medication as well as the pain, I lose count of my rakaats read in Salaah. To be safe I read an extra rakaat when I’m not sure as well as make sajdah sahw. Is there anything else I can or should do?

Q: During salah, I frequently forget any fardh and due to which I do sajda e sahw, am I correct?

Q: I always feel like I did a mistake in prayer so I always prostrate twice after I say salaam. While I was doing prayer today, in my mind something came that said if I prostrate, I prostrated to something other than Allah but I still prostrated. Did I commit shirk?