Could i have lost my relationship due to not being emotionally available because i smoke weed?

I have been a constant smoker for 7 years and just ended a relationship of 5 years and a 2 year old daughter due to "unhappiness". I feel as though we could have worked things out but she has doubt. We still get along and talk due to my daughter but Im lost now, lonely and looking for something! I miss her and our family we had. We had a house a dog good money flo were engaged but through out the relationship and expecially after our daughter was born we just kinda grew apart, we became friends. I'm pretty productive in everyday life, i don't hang out with the bad crowd and have a good job. I enjoy smoking pot but im not against quiting, i know it will be hard but i just want some good logic and advise on if i could be emotionally shut off because of pot. I lost my mother when i was 9 and sometimes link my relationship problems with that, not having a mother growing up.