Can you tell me how to recover from a strained calf?

Yes: Recommend stretch and exercise to see if it improves. Consider ice/heat, NSAIDs and even some mild pain relievers while you are healing. If not, then see a sports medicine specialist to evaluate your options for treatments. You may need imaging to determine what tissue is damaged so that treatments can be targeted.

May take months.: The calf muscle is a very important component in walking as well as keeping our balance. Without it, we could not stay upright. With that in mind, it is used quite a lot. Depending on the severity of the injury, it could take months. If after 6 weeks, you are still in pain, I would get a proper evaluation on what is wrong with it. In the meantime, rest ice/heat and NSAIDS.