Whilst you think about what to do about it medium/longterm with the FA:
Max out your premium bonds holding £50k - you can withdraw anytime. maybe 3%+ tax free interest per year.
Check out
https://forums.moneysavingexpert.co...-access-acs-ranked-top-of-the-pots-no-chat/p1 for best on access savings rates (gets updated every few days)
If you have trusted partner/kids, give money to them to invest in same ways, but get a document going of any monetary gifts you give away per financial year (if you unfortunately die within 7 years of a gift being given, then they'll be liable for inheritance tax purposes).
Spreading the money to others, (especially premium bonds - 0% tax) lowers your tax savings burden, it's only about £3k these days, before the tax man wants a slice.
Make sure you have sorted your wills and LPA's, as presumably you are now near the 'head of the family' level.