1st update today,kernel update won,t allow reboot thanks to timeshift able to bring up previous day

i know i need to update but after trying to reconfigure boot sequence i just settled on timeshifts previous days installation without update kernel,this has taken up most of my day,switched from win10 to linuxmint 19.2 a couple of days ago and am new to nomenclature,system worked beautifully while i concentrated on learning curve until kernel update,boot sequence seems to be off not quite sure since there is no troubleshooting mechanism in os.please,would appreciate any help