Do I cross your mind? Ever?

When you loose something or someone it hurts.  For the past 3 years I've been through so many ups and downs - feeling happy one minute to crying the next due to the loss of someone, yet still feeling something for this person.  Loosing someone, yet still feeling love for this person has been a vicious cycle for me.  I'll go happy and strong for about 3 months and then completely fall apart for the next month.  WHY???  Does anyone else experience this?  There are moments where all I can do is cry because I miss this person so much.  I have dreams about this person.  I go to bed thinking about this person and I think about this person multiple times per day.  And I can't help but wonder if this person ever thinks of me…..Do I even cross this person's mind?  Does this person ever think of me?