Don't rush it! My wife started at 0.5mg because she was worried about side effects. If you've been on 1.5mg for a couple of weeks already, try bumping it up to 2mg for the next two weeks. Then, increase it by 0.5mg every two weeks until you feel like the hunger isn't getting to you. For example, I inject Sunday night, and if I start feeling hungry again on Thursday, I know it's time to increase the dose again. If the hunger doesn't come back until Saturday, I stay at the same dose.
Splitting the dose isn't really necessary to make it more effective, IMO. It's more about reducing side effects. I think taking 3mg in one shot each week is better than splitting that into two 1.5mg injections every 3.5 days (assuming you don't have noticeable side effects). Splitting won't hurt you, though. I just wanted to give you my perspective.
It's good that you're being patient. People who take their time tend to be more successful in the long run. Think about doing a gradual increase; there's no need to rush to the highest dose possible if a lower dose is already giving you results.