I do not practice specific staying in the now actions. For me the past is important as well as the present. One thing that helps me is thinking of all the times l or someone I know overcame the same problems. For instance, I am now getting ready to move to a new place, a senior living community. It has stressed me and stress leads to anxiety. I just think of all the times I have moved before and came through fine. I can also think of my grandparents moving to a retirement community after living in their house for 50 years. I have only lived at my present place 8 years.
Another thing is to look for possible anxiety causers. Keep track of your times of anxiety and what was happening at the time. It might be a situation or it might be food you are eating or drinking. After a while look for patterns, any common things that happened at the time of the anxiety. Also as mentioned in a previous post, look into anti-anxiety meds. For me my antidepressant med helps with my anxiety. If you have unresolved problems, try thinking of something to do to resolve it, even if just a trial to see if it works or one small step in resolving it. Do not be hard on yourself as we all struggle with what we should do, but we all make it through.