A relatively good day today. After some research I found that supplements with magnesium and calcium relax muscles and have been know to help with jaw clenching during sleep.
I got some and took a pill. I hadn't realised that my jaw muscle was so incredibly tense, even during the day! After an hour my jaw had relaxed and the pain around the extraction area stopped. I'm going to take another pill an hour or so before I go to sleep, hopefully it will stop me from clenching. The molars on the left are still sensitive but hopefully it'll get a chance to heal and settle.
I think I started clenching because of the stress of going to the dentist but it continued because it didn't seem to heal and the area stayed sore and sensitive (basically I kept clenching because I clenched). Depending on how it goes during the next week I'll see if I'm going to discuss it with my dentist next week. If the pills work I don't see the need for a mouth guard.
Finger's crossed
for it to work during my sleep!