Well, for your hamstrings , ITB and calf i would say, give ur muscles enough rest. During rest period, do lots of icing on those muscles. once rest has been given for around 2 weeks depending on the seriousness of the injury, start stretching the muscles all of them really slowly. Stretch them for 10 seconds per repitition and do it ten times per session. Inially do 1 session everyday, later after a week add 2 sessions more. Then once you can maintain the stretching for more than a minute in a stretched position, then it is ready to be trained in proper. then start the strengthening.

For quadriceps, tighntness in the form you are explaining cannot be nerve related. just go for bending your knee in prone lying position and keep it there for a minute. do it 5 times, 2 session/day. Will recover soon.

Do stay in touch and keep giving me feedback....