Muscle back pain in the lumbar area

I have an occuring pain in the area around lower spine into the lats (muscle in back) right side and lumbar pain it has been going since mid jan this year thought it was a knot from exercise but actually think its more
a sprain nothins sore to touch or herniated bruised red on the outside
Bending over walking small exertions yoga stretches etc cat camel downward dog work tried all that but its this stiffness in the lumbar thats always there with this lat sprain
Getting inflammation down with fruits ice heat salt baths Magnesium gel, voltarol nothing presciption yet.
Then was thinking it could be cause have a soft mattress topper which actually brought to go over the hard mattress already have but cant sleep on back only to the side so would a foam firmer mattress etc help
Its the time its taking to heal thats worrying normally bounce back fairly quick not with this back pain