Actions to establish or modify alimony, maintenance, or support are exempted from the automatic stay provision. 11 U.S.C. § 362(b)(2). Because these actions are exempted from the stay provision, you may proceed and the Chapter 13 filing will not affect your claim for support. In addition domestic support orders cannot be discharged in bankruptcy.
As regards the unpaid medical bills I suggest you contact a bankruptcy lawyer to assist you in collecting this debt as it may be more complex than a fixed support order.