Anxiety doesn't come from thinking about the future, it comes from trying to control it.
I have found that anxiety around almost anything is due to control issues.
You have a preconceived vision for the results, and now all your efforts are pointed toward that end. If things start to go awry, you will get anxious. Once you are projecting your thoughts and/or feelings on the outcome of anything, there will be anxiety. Because you are investing emotion in the future.
You cannot control anything! Control is an illusion. No one knows what will happen tomorrow, let alone in a year. What happens, happens and you do not want to have an attachment to the result. That is where the anxiety starts.
You need to go with the flow, what you want may happen and it may not ......you need to be OK either way.
You can prepare for the future, purchase life insurance, a retirement savings plan, or write a will. Having your affairs in order will no doubt make you feel in control, and therefore reduce anxiety. You can prepare for any eventuality, but you have no control over when, how or what actually happens.
"Worrying, obsessing, and controlling are illusions. They are tricks we play on ourselves." Melody Beattie
"If you want real control, drop the illusion of control. Let life live you. It does anyway." Byron Katie
You are here to enjoy the 'ride,' what will be, will be. So enjoy your stay on earth, and let go of the illusion of control.