some sort of head injury?

So I have an older female cockatiel and the past year or so my family and I have noticed that she'll randomly fly into walls or fall off her perch. But today I noticed she's entirely off balance... she does have and old injury on her foot but that's completely healed and scarred over etc. This I think might have to do with a head injury... she moves her head all weird and faces slightly up and whenever she tries to fly she flips backwards onto her back as if that was up... and when she climbs she uses her beak to find her way and uses her claw and beak to keep her steady cause she gets off balance easily... its like she's dizzy or something... please help :(