Hi there
I also agree that you need another opinion (a good physiotherapist would be a great place to start) and ultrasound/Wikipedia reference-linkMRI to determine the extent of the damage. it is possible that you have damaged the achilles tendon in some way, but in some people there is also a plantaris tendon (not everyone has it) which can also rupture independently of the achilles but initially it presents very much similar to an achilles rupture, although the restriction in active ankle movement doesn't last as the swelling and bruising subsides. you may also have torn or damaged other structures around then ankle.

while you can happily live without a plantaris and it will just gradually heal (your body takes care of the left over bits of muscle in time), but you do need an achilles tendon so it's a good idea to get further tested to see exactly what the damage is now that the acute injury is 3 weeks old.

good luck
msk101