Sorry to hear about your unfortunate situation. I don't know how "eager" you were when you collected as teenager (meaning how much research you did and knowledge you gained)
I will not be able to assist you with UK coins. However, i would suggest that you divide your collection. (the more "scarce/rare" ones from the more "normal/common" coins)
I'm aware of different varieties (high tide / low tide) etc. Also keep the coins with silver content in mind.
You can try to contact a local dealer in your area but keep in mind that they will offer substantially less than catalogue price.
Also try to find a Omnicoin member willing to assist you with the scarce/rare coins ... https://www.omnicoin.com/search/?tp=2&country=United+Kingdom&kw=
Hopefully other forum members may also have other suggestions