The IRS never received my federal return. After 8 weeks of waiting, my transcripts are still blank. THE USPS tracker still shows it "running late for delivery"

See if it shows up in the IRS tool:

If you are due a Federal refund, you can use the IRS "Where's My Refund" tool.    Is there any message there?

https://www.irs.gov/wheres-my-refund

Since you said "need the money", I assume that means you are getting a refund.    But even if you had taxes owed, then you can still try the IRS WMR tool by entering $1 (without the dollar sign) as the "refund" amount.   It  works for me each year when I owe taxes due to at least let me know they received it.   It's a little trick I learned a few years ago.   It may not work for everyone, but easy to try.

If you still can't find any evidence of it, I'd phone the IRS to see if they can tell if they received it, or if they can at least suggest what you should do in that circumstance.

IRS:  800-829-1040 (7AM-7 PM local time) Monday-Friday

When calling the IRS do not choose the first choice re: "Refund", or it will send you to an automated phone line.

• First choose your language.  Then listen to each menu before making the selection.
• Then press 2 for "personal income tax".
• Then press 1 for "form, tax history, or payment".  
• Then press 3 "for all other questions."
• Then press 2 "for all other questions." 
• It may then ask for your SSN, but do not enter it.  Just wait.   If it asks for SSN a second time, still do not enter it. 
• Then it will get "tired", and you'll get another menu.  Choose 2 for "personal".
• Then in the next menu choose 4 for "all other inquiries", and it should transfer you to an agent but expect a long wait.
• I usually use a speakerphone so I can work on something else while waiting.