ANSWER: Spiders can mean a variety of things depending on the type of spider, how it is behaving and where you see it. Generally, in daily waking life, living spiders are guardians – friends if you will – who look out for us, provide protection and have the message that we need to be using our own wisdom about a situation that we find ourselves in.
They do seem to get a bad rap given that they look quite scary and can freak a lot of people out but if you find yourself seemingly surrounded by spiders it isn’t necessarily a bad thing.
Spiders in dreams can mean very different things as to our subconscious they are enemies to be overcome.
However, in this instance I would say the dreams are prompted by the guilt you are feeling over accidentally killing one. Spiders can and do sneak into the strangest of spaces which would explain finding one in your sketchbook and I would say that the message is perhaps more that you are ignoring your own wisdom in favour of something easier to think or feel about something or someone. Try sitting with yourself in meditation or whatever else it is you do that allows you to clear your mind of all other things and focus on one thing. Ask yourself if there is something you are ignoring that you should be paying attention to. Perhaps there is something you should be wary of happening right now and the spiders are showing up as a means of protection while you figure it out.
I would also suggest as a means of easing your own mind about this accidental death would be to hold a little ritual honouring the spider for his sacrifice in bringing you the message you need to hear right now. Maybe light a candle, say a few words and express your sorrow for its death at your hands and allow yourself to move on and forgive yourself for what was a total accident and could not be helped.
I hope this helps,