Lower back + knee + shoulders not improving!

Short summary: Pain, tightness etc. in lower back (8 months), right knee(7 months), left knee (5 months), and both shoulders (6 weeks), which isn't improving despite me doing stretches, foam rolling, mobility drills etc.

Hi all,

I sprained my lower back doing deadlifts last summer, which still hasn't healed.

Then, after a month or two, my knees suddenly started getting tighter, slightly in pain, which progressively injured (never too crazy, but enough to prevent me from lifting, or even any other strenuous movements), which then spread to my left knee. I have no clue about why/how these happened.

Then, around Christmas, both my shoulders started showing similar signs of tightness, and low pain. Again no idea why.
There is also a fair amount of clicking involved when I move my shoulders or knees as well.

I have done quite a fair amount of rehab, stretches, rolling etc, but everything is just stuck in terms of progress. I have no idea what to do and am quite frustrated!

Thanks in advance for any advise! I would really appreciate your input, and to see what you can make of this!

Have a lovely day! :)

Best,
Ayush