Severe sprain a year ago its still swollen around my ankle and top of foot. it makes a poping noise when i walk and gives out. should i wear a brace?

Ankle instability: You may have ligament damage at minimum. Best see an orthopedic surgeon/sports medicine specialist for further evaluation. MRI may provide more information than X-ray.

Yes: A brace is a good idea. But I recommend you see a podiatrist for evaluation and treatment. It sounds like the ligaments may have healed a little loose, which is very common, and this is leading to instability.

1 year: after an ankle sprain and still having swelling and instability would give me a high suspicion of ligament damage. A brace may help, however getting an exam and likely MRI of the joint will give you the best diagnosis and treatment plan!