OP,
From what you have posted, it sounds like you have a need to be in control. Being proactive by getting tasks done as quickly as possible, even if there isn't a close deadline, is a product of you conquering the moment in time (re: undone task(s) when you feel vulnerable, insecure, and out of your so-called element. In my opinion, finding ways to distract yourself from the inner angst and insecurity you find yourself in on a regular basis is not the answer. Distraction does not force you to honestly deal with the origins of your trigger(s), and work through them in a forthright manner. What it does do, is keep you on the same emotional merry-go-round.
If you want to work towards freeing yourself from the merry-go-round, you need to put yourself in new situations, that force you to act outside of your normal (emotional and physical) routine. What I am speaking of is something as simple as making a point to make eye contact and speak to a stranger before he or she speaks to you, whether you are ordering the same food and beverage at your favorite places, (as I think you are prone to do) or while you are walking along the street etc. Every day, say hello to 5 strangers. It doesn't matter whether they say anything in return or not. Get some playing cards, coffee stirs or the like, and empty the contents on the floor in several areas you frequent at home, so that the cards, stirs, or whatever object(s) you have chosen are disorganized. Leave the object(s) on the floor for 24hrs before removing them. Each time you see the mess on the floor, you will have some anxiety, because you feel strong urges to clean the floor.
Having a type A personality is not a bad thing, unless it is allowed to take control of a person's life. Often times, people with type A personality tendencies see their day to day life as various tasks that need to be conquered. They maneuver from one completed task and person to the next. While having this mindset can allow one to accomplish many things at once, it can also hinder one from experiencing and living in the moment(s) of each day. Many times, a person with type A personality tendencies will often feel that he or she could have achieved more during the day, or conquered the task(s) better if it weren't for x,y, or z.
Life is not about conquering the moments. Life is about immersing ourselves in each moment we have. Instead of fearing or shying away from that which can make us feel angst, anger, sadness, joy, or love etc. we turn towards it, thus making ourselves vulnerable in some way. And it is this vulnerability, that can lead to growth, if we allow it.
Congratulations on your new job. I wish you the very best. I hope you will try some of the things I mentioned as I believe it will be a help to you.