There are two parts of e-liquid which contribute to the throat hit: the PG and the nicotine. If your e-liquid is feeling too harsh, it could be that your nicotine level is too high or you have a bit of an intolerance to the PG. Picking a lower-strength liquid or one that's higher in VG should feel better for you.

However, you may also find that lowering the wattage/voltage of your device will also lower the harshness. If you have a device such as the SERIES-B Tilt, it is worth checking what resistance the coil is being read as. While a variance of around 0.1ohms is normal, if your coil is showing as far different from what it should be (For example, showing as 1.2ohms instead of 1.8ohms), this can make the resulting vapour feel very harsh. In this case, check that the coil and tank are screwed in properly but not too tight, or change the coil for a new one.