He was excluded from the life for a long time, and he feels almost physical pain in his communication with people. (?)

He was living as a hermit for a long time, and now he feels real physical pain when he communicates with people. (?)

He was living as a hermit for a long time
"For a long time" implies Present Perfect or Present Perfect Continuous.
Инфа - сотка!😁👌

Вторая часть предложения - Pres.Perfect, because it goes about the result by now.
Другое дело, как все это сказать))

Такая мысль была!)) he has been living?

Да, или - He has lived - if it comes about the period which is finished already, but is stiil important for the present)

Pink Peony, since it's clear from the context that this person is not isolated from society anymore, you should choose the former.

Holy Moly, you mean if the period isn't complete I have to use Pres.Perf.Continuous, right?
Thank you very much for the translation!

Yes, if he’s still living in isolation, then it should be “He’s been living in isolation for many years (now)...”

But in that case, the Russian original should also be «Он долгое время живёт в изоляции…».