First, if you haven't seen it yet, check out the IRS Taxpayer Advocate Service's I Don't Have My Refund page. It discusses different things that can go wrong with receiving your refund and what to do about it.
From your post, it sounds like you've tried all of the normal things to do, and you've tried calling in to the IRS. What you might not know is that there are local IRS offices that you can visit and talk to a real person face-to-face. Hopefully, you'll find someone helpful there who can either explain to you what is going on or put you in touch with someone who can help. To find your local IRS office, go to the Contact Your Local IRS Office page and click on the Office Locator button. Office visits are generally by appointment only, so you'll need to call the number for the office you want to visit and make an appointment.
Alternatively, if you can't get anywhere with the IRS, you could contact the Taxpayer Advocate Service, which is an independent organization within the IRS that exists to help people with disputes with the IRS, and they have an office in every state. You could try contacting them and seeing if they can help you with your issue.
To answer your question about this year's tax return: At least for the federal return, your refund from last year does not really affect this year's tax return. You should be able to file this year's return no matter what happens with last year's refund. That having been said, you should get the refund matter straightened out as soon as you can.