Why Can't I Ask For Help?

So, this is another self-reflection/found something else that's wrong with me type of post.

Ok, cool.

So yesterday my friend and I decided to go to a careers event together (which is tonight) but it's about a 15/20 minute drive. She suggested that I ask our mutual friend to drive us and see if he wouldn't mind. Now, instead of me just to ask him and see if he says yes or no I delayed asking. I went as far as to check uber and train options first all while under the facade that my phone was dead (I even put my phone on airplane mode to go with the story). Until I realised I don't actually know how to ask for favours. If it's something simple like pass the milk or do you have a spare pen I'm ok but it seems that anything beyond that I struggle. What makes this even more ridiculous is that I'm the complete opposite when it comes to other people. In theory if I was the type of person that doesn't do favours for others then my inability to ask for favours would make sense but no. I'm the type of person that doesn't mind helping people out as much as I can, to the point where my friends know that no matter what time they call me I'll answer the phone and be on hand to help.

This isn't the first time I've realised that I can't ask for help but it really became an issue when I found myself faced with potentially going into surgery alone. After the fact, when I was scolded by my friends, my flatmates and my family I realised that I had effectively put myself in a very scary situation without leaning on my support system. This pushed my inability to ask for help to the top of my very long list of problems.

Ok, so the problem has been identified so how do I fix this? I've tasked myself with asking for 3 favours this week that I wouldn't mind doing. To be honest, I have very low expectations of how well I will do but let's see. Also I want to find out why I struggle so much. In my head I know that if I ask, my friend will probably say yes so that's not why I don't ask. Also, I tend to surround myself with brutally honest people so if they can't or don't want to they will say no, so the fear of rejection isn't the issue.

Which begs the question, wtf is wrong with me?