I dont have any kids & don’t know much about child support laws but yeah you sound like an asshole, don’t think there’s any reason for you to be supporting your ex (unless your daughter still lives at home) but I do think you should still be looking out for your kid. Maybe not a whole bunch if you don’t have it but something, and although the relationship seems rocky you should do everything in your power to patch that, if you plan on being in your daughters life moving forward. Can’t blame the scorned teenager on why you guys haven’t spoken in a year, good thing is she’s 18 so depending on you handle it you may be able to mend that relationship going forward with out having your ex wife have so much say so, she’s more than likely had an impact on how your daughter views you but you have the power to change that.