Help, I am in a loop

hi!
I am trying to log in to Manychat and link it to my instagram. I had an account before and must have used my gmail to sign up. It keeps saying that a request has been sent to the OTHER account to link the two, and when I go to gmail and click: “view request” it just loops back to sign in to Instagram again and again says that it’s sent a request for access from… me. 
I tried to go back and just sign up with gmail but the loop is created now - 

I’m just going around in circles. Please help? Thank you!!!