NASHARIF,
Welcome! When you say you were found "unfit", by whom? Was this a guard or reserve administrative determination or part of the Disability Evaluation System (MEB or PEB)? It is confusing, because if you are unfit, you should have been retired or separated.
As far as the question about raising or lowering your rating, which "they" are you talking about? The VA rating can change over time. The military is not bound by VA rating decisions (though they are good evidence of what a correct rating should be). The military, once it rates you, is locked into that rating (unless you are temporarily retired).
As far as the SSB, it appears that the answer depends on which period of service the injuries were incurred in:
US CODE: Title 10,1174. Separation pay upon involuntary discharge or release from active duty
Title 10 USC § 1174, "(h)(2) A member who has received separation pay under this section, or severance pay or readjustment pay under any other provision of law, based on service in the armed forces shall not be deprived, by reason of his receipt of such separation pay, severance pay, or readjustment pay, of any disability compensation to which he is entitled under the laws administered by the Department of Veterans Affairs, but there shall be deducted from that disability compensation an amount equal to the total amount of separation pay, severance pay, and readjustment pay received, less the amount of Federal income tax withheld from such pay (such withholding being at the flat withholding rate for Federal income tax withholding, as in effect pursuant to regulations prescribed under chapter 24 of the Internal Revenue Code of 1986). Notwithstanding the preceding sentence, no deduction may be made from disability compensation for the amount of any separation pay, severance pay, or readjustment pay received because of an earlier discharge or release from a period of active duty if the disability which is the basis for that disability compensation was incurred or aggravated during a later period of active duty. "
(The above applies under Title 10 USC § 1174a. Special separation benefits programs, subsection (g)).
If you were injured during a later period of active or reserve duty (which it sounds like is the case), they should not recoup SSB from military disability compensation.
It seems that the SSB should have been deducted already from your VA compensation. Was it?
Thanks for this question, it is not a common one.