i have gone through your case . it is very common problem it is tendinitis/ over use of muscles . what you should do is do routine work as usual do not lif t heavy objects apply hot packs daily for 30 mins in morning and evening in calf region in lumbar region and in neck region. take tablets of painkiller + muscle relaxant
morning and evening for 5 days . after 5 days do quadriceps and back and neck strenghening exercises.. do not go to gym alot of videos are present on youtube by various physiotherepists or yoga
videos . for your body parts which feel colder ..apply hot packs over them ... at last be happy and be positive in life ..