I actually wrote a reply to this earlier this morning. It took me an hour, and i'm really annoyed to see that it didn't work. The gist of my message was that there are many things that can cause your pain. The most likely based on what you'v said is a quad contusion. With the contusion there is risk of rebleed within the first 10 days and also the blood can travel down and cause patellofemoral joint irritation if it's low enough. What this means is that you should be doing any sport right away, and you should be seeing a physio for specific rehab. From what you'v said I cannot know what is wrong I can only come up with a likely diagnosis that i would confirm when assessing you.
The 4 stages of rehab of a contusion are: control haemorrage; restore ROM pain free; functional rehabilitation; gradual return to activity.
depending on the severity and the exact muscle involved will let us know how fast you can go through these 4 stages.

Based on what you'v said I feel you should be seeing someone to get specific rehab. Im sorry that I'm not really able to give you specific rehab guidelines without examining you. To be fair, refrain from sport and aggrivating the pain until you can get specific exercises from a physio.