Lucy,
The answers to your questions depends on a lot of info you haven't provided.
1. How was the tear diagnosed (Dr or Ultrasound)?
2. Where in the biceps is it?
3. How big is it?
4. Are the tissues around the tear normal?
5. How far apart are the 2 torn muscle ends?
6. How old are you?
Fortunately for you, how excruciating the pain is following a muscle tear is not indicative of how long it will take to heal. In fact, partial tears are often more painful than complete ruptures. The reason for this is thought to be the fact that the intact muscle fibres at either end of the tear are stretched and therefore generate pain signals. With a complete rupture, there are no stretched muscle fibres to generate pain.
My guess, on the limited info you have provided, is that you will be in some pain for 1-2 weeks. You will be able to resume some gentle upper limb training within 6 weeks but the healing tissue will not reach maximum strength for at least 6 months. It may be wise to avoid techniques involving forceful contraction or stretching of the torn muscle for that long at least.
It's too early to predict the likelihood of recurrences.
I hope that this is of help.
Cheers,
Robert Gassin
Melbourne ShorinjiKempo Branch
Australia
"Never fight an idiot. He'll bring you down to his level and then beat you with experience"