Under the lump on my ankle i think it's called the tallus bone underneath there's a swell that hurts. i'm doing track for school too any ideas what it?

Flatfeet?: Do you have flatfeet? This could be pain due to tarsal tunnel syndrome or pain of the posterior tibial tendon due to flatfeet or injury. If you have good bloodflow i would try icing it, compression with an ace and seeing a podiatrist in person to fully evaluate it. You may also benefit from supportive orthotics (not ones you get at a pharmacy).

It really depends : If its on the inner part of the and or the outer. You may have posterior tibial tendonitis, but, that's a guess based on the limited info provided. If you run track, i would advise a visit to the foot doc so you don't make your problem worse.

Tendonitis: The tibialis posticus runs medially and the peroneals run laterally. Overuse could cause tendinitis. Have it checked out by a podiatrist. You may need orthotics to keep everything in good alignment.

Lump: As stated by dr's kass and nemes, you should see your podiatrist for an evaluation to determine not only what and where it is , but why it is there. Good luck.