Can't boot into TWRP recovery *pls help*

Hi, I'm unable to boot into any recovery, as when i attempt to flash from fastboot USB, disconnect USB cable, select "reboot into recovery mode", my phone vibrates for a second, stock htc boot logo with red text along the bottom, but only for 1 second before going back to fastboot.:confused:
it looks like this:
experimental software build. do not distribute without permission from htc, or punishment will be implimented.
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fastboot specs:
software status: Modified
UNLOCKED
A51_TUHL PVT SHIP S-ON
HBOOT-3.19.0.0000
os-1.05.980.1
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PLS dont do anything to mah phone with this info (if its possible)