A simple opamp circuit can do the job.
Please supply more detail like:
more detail of the load cell's output
a schematic of your 555 circuit
a more detailed description what the effect of the load cell's output on the 555 circuit shall be
what power supply(ies) are being used. Note that with a single supply you may (or may not, depending on the circuit's details) need a rail-2-rail opamp
Thanks for getting back so soon. The load cell is this one: https://www.ebay.co.uk/itm/314541831911?var=613097026384 but I don't want to use the HX711. I want to input the load cell into the NE555n pictured below. I made it years ago and have lost the schematic. Also, I may be in the wrong forum as I know next to nothing about electronics. Thanks again. edit: the 555 is 9V I'd like to excite the load cell with something similar (though I think it likes 5V. I've just seen this: https://maker.pro/forums/threads/audio-amplifier-to-amplify-a-load-cell-signal.280337/ Will read up on instrumentation amplifiers.
There is a way to do this in a single chip but I sense maybe you do not have a mixed signal
background ? Eg. no specs given, VCO range, VCO output waveform, accuracy, load cell range......