Is there any rule about ending relationships in early recovery?

Is there any rule about ending relationships in early recovery? I know that people in recovery aren’t really advised to start romantic relationships but I was just wondering if the same thing held true about not ending them. The thing for me is I am 5 weeks clean from a very long and very heavy marijuana habit. It was very tough but it is getting easier and honestly I am feeling better now than I have for a long time. I think now that I am looking at my life through less clouded eyes I am seeing that a lot of what I thought was good for me was just stuff that I had built around me that wouldn’t interfere too much with my getting high every day; like my hot but not very challenging girlfriend. I thought we had a great relationship but now that I actually want get out of the house and do things I am finding that she is kind of limiting. She was great for someone to keep me company while I was high and to have sex with but I am not sure that there is much more to us than that; which is very sad since we have been living together for more than 4 years. I feel like there is nothing I can’t do right now and I just want to make up for all the time I have been wasting. I realize I sound like kind of a jerk and she was really helpful in helping me kick but is it ever a good reason to stay with someone just because they have been nice to you in the past if it is not working in the present? IS there any reason why my recently quitting pot would be clouding my judgment here?