Let me be the voice of experiance here. I broke my arm right above the elbow and a bone in the elbow itself nearly 30 years ago now. I didn't do anything for over a month except stay at home and have my mother give me one drug for the pain that made me sleep and another drug to wake me up just so she could give me the drug for the pain that made me sleep.
Once they let me go back to school, I couldn't really over do it because my teacher was an old family friend and the cast and sling in a crowded school just doesn't really work for being active. But, once the cast came off, I was right back doing the very things that caused me to break my arm and elbow to begin with.
Now I am 35 years old. I have days when I can't hold anything in my left hand, which is the hand on the arm I broke. That elbow does a lot of cracking and popping. Im not allowed to lift anything over 5 lbs with that arm and if it rains, I curl up in a ball, hide under the blanket and pray the pain will eventually let up enough that I can stop seeing rainbow colors.
There isn't anything any doctor can do for me. Admitedly there were complications to my break that you don't have. If you become to active to fast you can cause a lot of the complications I had. Im telling you right now, lay off the exercising, get a physical therapist when the cast comes off and slow down. Your falling off your bike was the universes way of letting you know you needed to slow down. So listen to it and take it easy. Otherwise, the universe will throw a brick at you next time that ultimatly will cause you to pay a much greater price than you are now.
Doctors won't do anything for my arm because I can use it. Everyone is just sitting around waiting for the day I can't. Then maybe they will try to fix it. But, by then it will be to late. Truth is, it probably already is. So I have to appreciate my ability to use my left hand and arm while I have it. Don't over do it and end up in my situation.
At the same time, don't under do it and let the mucsle atrophy. Go see a specialist who will know just the right amount of exercise for you right now. Do what your told you can do and forget about the rest. The idea of lifting weights with a broken elbow is mind boggling to me. Let the weights go and when it gets to the point you can walk without pain, then put weights on your ankles and walk, if the doctors tell you thats okay. But, leave that arm alone to heal properly.