Share your experience!
i reinstalled instagram but the problem has not gone. I use a fast wifi connection and 3g mobile data.
Have you tried to clear data for instagram app and log in again?

@Anmol1 Not sure if reinstalling will have the same effect as clearing data as sometimes data is left behind if you only uninstall the application.
talk about rudeness, perhaps you can be a bit more specific and use numbers instead of "fast connection"
download speedtest and report back
Are you able to play youtube videos? you should contact Instagram regarding this problem
Might be something local so I think uli got a point here.