The chances of AVN are very less for thisbkind of fracture. The fracture usually takes 3-6 Months to heal fully. At 45 days this is too early to do anything strenuous. You can walk and mobilise and do the Physiotherapy. Avoid doing any long walks or any running for few more weeks. Make sure you stop smoking and consuming alcohol until the fracture heals. It is very important to give the bone all the chance to heal, considering your age.