Can state garnish 90% of my wages with little or no notice?

You need to consult with an attorney right away. Something from what you write seems wrong: under federal law, wage garnishment is limited to around 50% of your "disposable income," which is your income after required deductions (e.g. FICA); there are also some limitiations built in make sure that low-income tax payers have enough to live on (e.g. if you are earning only a little more than minimum wage, only a small amount of your income can be garnished). Therefore, it may be that there is an error and they are garnishing too much. An attorney can help you determine if that's the case and lower the amount  garnished if appropriate, while looking into longer-term fixes (like challening the garnishment entirely and getting your money back if the money was incorrectly charactertized). Good luck.

You may need to seek legal help with this to give you a little bit of clout behind the matter.  The state has leverage here and they have power beyond belief.  Here is the general rule on garnishment for Maryland:

"Disposable wages are defined as the amount of wages that remain after mandatory deductions required by law, plus medical insurance payments. The amount exempt is the greater of 75% of disposable wages, or $145 times the number of weeks in which the wages were earned (in Caroline, Kent, Queen Anne's and Worcester 30 times the federal minimum hourly wages due under the Fair labor Standards Act.) (Annotated Code of Maryland, Commercial Law Article Sec. 15-601.1). A judgment creditors report must be sent each month to the debtor and employer. "

Good luck to you.