The two red marks are too far apart to be from any British spider. If the two marks on your finger are from the couple of times this week you were woken up, then again they can't be spider bites - each one would leave two pinpricks close together. What makes you assume it must be a spider? A biting insect is vastly more likely. Spiders of a number of species commonly occur inside houses and in gardens even if you don't see them, so just because you found a large spider (probably one of the larger house spider species) 3 years ago does not mean at all that this spider was responsible for a bite - you just happened to see the spider then. Few spiders have fangs that can penetrate the human skin or have any inclination to try.
PS, most photographs on the internet and virtually all photos in the media purporting to be of spider bites or the results of spider bites are nothing of the sort and nothing at all to do with an spider.