Are feelings of doom natural with anxiety?

Could be. Yes. Anxiety is comprised of thoughts of uncontrollability and unpredictability of future events. Anxiety as a process prepares us for future threat (in moderation). Related to anxiety is panic, which is the clinical manifestation of fear. Panic is coupled with thoughts and feelings of impending doom, and danger, so that one has to "be on the look out.".
Anxiety. Yes feelings of doom are common with ongoing anxiety.Seek psychotherapy as it is quite effective in treating anxiety. Best.