I had AWFUL back pain from the very first week of finding out I was pregnant and yes, it had me in tears! I still have it over 3 months postpartum too--so I can readily sympathise! You poor mama-to-be! It feels like someone is beating you over the back with a baseball bat, doesn't it?!? Yeah, I get that! I even missed a trip northwards for a special concert in celebration of my hubby's and I's 2nd-wedding anniversary because the pain in my back was just too much to take for the trip!
Apparently, the hormone relaxin (necessary during pregnancy to relax and prepare the pelvins for childbirth) causes our ligaments and joints to all go slack throughout the body! This can, in turn, cause some instability issues! I actually thought that after years of diligent yoga and pilates sessions, I would be the much better during pregnancy aches and pains-wise. According to my physiotherapist, it has only exacerbated relaxin's effects on my body to the point of 'hypermobility' (have pelvic pain now too postpartum!). My pain is in my upper and middle back too which seemed to stupify most since lower back pain is more common during pregnancy--or so it would seem! Once the pregnancy hormones completely leave my body--I am told I should feel better though in choosing to breastfeed exclusively as I am doing, it will longer before this happens!
There are obstetric physiotherapists available on the NHS and I had a good one during my pregnancy. Talk to your midwife or OB/GYN about a referral! Ice packs and heating pads (on low!) can help as well as nice warm bath soaks (try some Dead Sea Salts) and if you have a good partner--have him massage you with some arnica oil (it is actually safe during pregnancy!).
A good exercise is to sit straight, fold your arms over your chest and turn to one side...Hold that position for about 30 seconds and repeat on the other side...Also, if your partner massages you--have him press his index finger into any really painful bits and rub deeply into the flesh there...Both of these exercises were suggested by the obstetric physiotherapist I saw and they helped! I also had some acupuncture and a professional massage done and felt a marked improvement for a good while afterwards!
Oh yes--try doing some pelvic tilts or the yoga, "Cat" position...Go into a crawling position and suck your abdominal muscles in towards your spine. for about 10 seconds at a time before releasing. Repeat this about 20 more times--or however many are comfortable for you!
Ensure you are getting enough calcium/magnesium and proteins too!
I hope you feel better soon!
Love the "Monty Python" reference by the way! Too cool!