No comment on the joint thing.

As far as tendons are concerned, they require proactive rehab and you have to load them. There are various loading strategies that a physio is best placed to advise on. Shockwave therapy has also been found to help.

Some pain during tendon loading during rehab is generally expected and not necessarily a negative sign, somewhere around a 4/10 at most.

Recovery is slow in the order of months, not weeks.

There is some evidence that taking a collagen peptide based protein along with vitamin c an hour before loading the tendon can help.