I (usually) have concerns about my language.
Correct, but the adverb often might be more suitable.
I'm usually being concerned about my language.
This is unacceptable. Compare 'I'm usually being asleep' / 'I'm usually being cold'. Use 'I'm usually/often concerned about my language'.
Stative verbs, being used to describe states, often are not written in
the progressive aspect, which is used to describe incomplete actions
We are buying the Tudor Revival house in Somerset.
*We are owning the Tudor Revival house in Somerset.
[Tense, Aspect and Time Concepts In English ... S.Suwono]
I concern about my language.
Incorrect. Unlike the participial adjective concerned, the verb concern doesn't take the preposition about without an intervening direct object, is strictly transitive in today's English, and means 'relate to', 'be a matter that ought to involve' or 'apply to' (or, in another sense, 'disturb/worry').
Note This answer assumes UK / US usages.