How long is it normal for a knee to be swelled up for for a Minor MCL tear?
sounds more than a minor MCL tear to me
Why has the sweeling moved from Inside of my knee cap to the front of my knee and also around the outside and slightly above my knee?
you have developed swelling inside the knee joint itself. This is what prduces the pattern of swelling you describe. The MCL is a big tough ligament on the inner ( medial) side of the knee, but not inside the knee. It should not produce this pattern of swelling. However it does attach to structures deep inside the knee such as the medial Wikipedia reference-linkmeniscus (often called the medial cartilage). So if the MCL is torn the The cartilage may have been disrupted at the same time or something else inside the knee may have been injured. This would be unlikely to show up on a simple xray.

I can walk and it gives way sometimes(not very often now) it just feels like it will, I am unable to twist it as it gives way straight away and feels like a very sharp pain?
The giving way is a common symptom with intra articular knee injuries and can be caused by either a mechanical fault or a nervous system reflex inhibition of the quads muscle that keeps you knee straight. This reflex is mediated by pain and swelling.

How long normally does an Minor MCL tear/sprain take to heal?
Ligaments are rather slow to heal but if it really is a minor one symptoms tend to die down in a matter of days. The full healing takes a lot longer - 6-12 weeks

However you clearly have more going on and you're right to be concerned about the diagnosis. It is common in the excitement of the accident for the medics to be more concerned about your spine and brain for obvious reasons - and things like this get overlooked. You have not received a proper work up your knee and an xray is insufficient testing. I would go to an orthopaeic surgeon again and get it fully looked at - probably needs an Wikipedia reference-linkMRI to look inside the knee.