ANSWER:

The prayers are valid as these are separate things. 

However, it’s totally prohibited to be disrespectful to parents as it is one of the major sins in Islam and you won’t be able to enter Paradise due to this. Allah will not forgive you until your parents forgive you so hurry in seeking their forgiveness before it’s too late. If your prayer is not able to make you a better person, this is a strong indication that your prayer is not accepted by Allah. 

I often get scolded by my parents and siblings. They say what is the purpose, what is the use of your prayer when you just sin, disobey parents, don’t respect your elders etc. Why do you pray when you sin so much? Your prayers aren’t valid because you disobey parents etc. Does prayer not get accepted in such case?