I’m sorry for your loss 
A bit more information would be useful 🙂
How old you are, whether you have a property, are a higher rate tax payer, have maxed your ISAs already, have a pension... all would influence replies and change the suitability of different options.
In the short term, whilst you don’t know what to do, I would put £50K into premium bonds. That’s the max you can hold. You cannot lose money, you won’t earn interest but your odds in the monthly prize draws will exceed your interest in a current almost certainly.
For anything else, more detail is needed.
Don’t be frightened by the amount though, and do nothing. There are options (like the premium bonds) that will do whilst you decide. You can probably get a free meeting with an IFA, but I’d start with thinking through where you are in life, and what you want to do. Work out how you’d like to live your life - and then work out the financial options around that.
At 20, I’d have quit my job and travelled for a year.
At 25, I’d have bought a flat that was suitable for me to live in or let out.
At 40, I’d have loaded it the hell into my pension!!!