My advice is to do whatever makes you happy, relationship or no relationship. In some ways I feel like my ex girlfriend and my lack of assertiveness is the reason I got to where I am today. I partied, drank constantly to keep up with her, ate and slept horribly and carted her around daily everywhere she wanted to go (she lived 45 minutes away). I put up with so much stress during that situation that I think it totally compromised my immune system after 8 months before I had to safe myself by calling everything off. She had a lot of family/emotional issues as well which just makes me shake my head for thinking I'd be her personal hero and save her from herself.
In my opinion, if you're with someone who loves you and adds no stressors to your life, it can only help your feelings of well-being. But it's all about finding that right person. If you pay attention to how you feel; if you're not being lifted up a majority of the time.. definitely get out of it and focus on yourself. Exercise good judgement and be aware of how you're feeling and act accordingly to your gut instincts. It's a minefield out there today.