Unfortunately, the deadline for filing for a refund from 2013 and 2014 has passed. If you are due a refund for 2015, 2016, 2017, and 2018, those returns will be processed and any refund will be issued.
To clarify - you would have needed to file each year separately, it cannot all be combined into one return and filed together.
Your question does not detail how you filed for all of those past years. It is not possible to file any past year returns using the current online software, which is ONLY for 2018 returns. You can use prior year software for 2015 though 2017, and those returns would have to be printed, signed and mailed--they cannot be e-filed. Software for years earlier than 2015 is no longer available, although if you owe for any of those years the IRS still wants you to pay. You could get the forms from the IRS or have them prepared by a local tax pro.
If you did mistakenly put all of that income on one tax return, please post back for further help--because you will really need help.