jwolf, you've posted on this problem numerous times here at MacRumors.
The answer remains the same:
Swap out the platter based hard drive inside for an SSD.
It will make a DRAMATIC improvement.
Why do you keep posting over and over again, when the answer will always be the same?
Young man, can you hold a screwdriver in your hands?
If you can do that, you can upgrade the MacBook Pro in about 15 minutes.
You are not helpless.
Why do you keep posting that it will be so "expensive"?
A Crucial MX500 will run you about $120:
https://www.amazon.com/Crucial-MX50...sr=8-1-spons&keywords=crucial+500gb+ssd&psc=1
If you're willing to settle for 250gb, it will cost only $72:
https://www.amazon.com/Crucial-MX50...=1528036422&sr=8-5&keywords=crucial+500gb+ssd
You'll also need one of these, price $13:
https://www.amazon.com/Sabrent-2-5-...478&sr=1-2-spell&keywords=sabremt+usb3+to+ssd
You need 2 drivers:
- Phillips #00 driver
- TORX T-6 driver
Both can be found at hardware stores or online.
When you have this stuff, connect the SSD to the USB3 dongle and plug it in.
Open Disk Utility and erase it to Mac OS extended with journaling enabled, GUID partition format.
The drive is now ready for the OS.
Now download CarbonCopyCloner from here:
http://www.bombich.com/download.html
Which version you download depends on which version of the OS you're using now.
Open CCC (it's FREE to use for 30 days).
Put your internal drive on the left.
Put the SSD "to the right"
Accept CCC's defaults and "let 'er go".
CCC will clone the contents of your internal drive to the external SSD.
When done, quit CCC and power off the MacBook.
Now... press the power on key and IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until you see the startup manager.
You should see the internal drive AND the external SSD as bootable drives.
Use the pointer to select the SSD and hit return.
Do you get a good boot?
It will look "just like the internal drive did", because "it's a clone".
If you get a good boot, now it's time to do the drive swap.
I'm NOT going to tell you what to do next.
Let's see if you can get yourself this far first.
It's easier than you think.