Research shows us that worrying is overall not good for us. However, if you find it difficult to change 'the worry habi'  then there is one way of worrying that is thought to be less harmful to you. The best way to worry if you have to worry (and the truth is that you really never do have to worry!) is instead of imagining yourself in the middle of a stressful situation sometime in the future imagine yourself observing yourself in that same situation. It seems that removing yourself just a little bit from the worrying situation helps us to deal with that worry and lessens the likelihood of it returning in the future. 
Better still, make a decision to write down all your worries for the day at the end of the day (a worry list) along with a to do list where you take one action step towards addressing the worry. That way you will be able to sleep better rather than having your worries going around and around in your head preventing you from sleeping. If a new worry pops into your headas you are trying to sleep then write it down -ideally without turning on the light.  It is crucial that you do this with a pen or pencil and paper or a little note book because if you use your phone or any electronic device the light emitted from the screen is likely to wake you up even more and worse still you may be tempted to search for something on ebay or check your instagram account etc etc. 
During the day when you are feeling refreshed and strong iyt can be useful to tackle your worry list. Look at all your worries and group them according to things that you can easily do something about, things that require a fair bit of effort and planning to sort out and those things over which you have no control or influence. Then you might like to admit to yourself that you really do have no control over those things and perhaps with a ceremony or just a deep breath outwards you may like to let go to the universe (or to god if you are religious) those things over which you have no contro. Recognise that the things over which you may have influence are much better areas to spend your efforts. Those worries that you can easily address-just make them into a to do list and deal with each of them as soon as possible. The worries that fall into the middle group rank them according to which you feel are most urgent and most important. Eg electricity will be cut off in 2 days is very urgent and very important and cannot be delayed. You need to write down an action plan to deal with this with steps too take eg. Find the bill, call up the electricity compan, explain your situation and ask for their help or ask a friend to do this for you, save money for the bill and pay it, long term save electricity by switching off lights, setting heat at a lower temperature, get a better paying job, switching companies. All of these are actions and will allow yourself to feel that you have accomplished something rather than just ruminating about what a problem it is. 
Worries that seem unsurmountable are often easily solved when you are willing to share them with another person. Two heads are better than one. SO share your worry with a trusted friend and see if they can help you overcome the problem. Beware of worry friends who enjoy having a contest to see who has the greatest problems and most worries-these friends do not have any interest in helping to overcome worries and are not going to help you at all. Find friends who genuinely want to support you and ask them questions like what woud you do in this situation? Rather than just moaning about it.
Worrying about relationships is a special case. See other sections about this as relationship worry often needs a very different approach.