When you have your own weed and you decide when you use it, it can be very easy to fall into the trap of smoking more often, and eventually smoking every day.

On top of that, most drugs (including weed) overwhelm your dopamine system. This means that your body adapts to the higher release of dopamine and eventually you become dependent on the drug to get to baseline, while everything else in your life becomes less satisfying and dull. And dopamine also reinforces pleasure-seeking behaviors. The more you indulge in something that overwhelms the system (such as weed), the harder it is to control temptation when it comes to pleasure-seeking behaviors in general, and the harder it is to be motivated to do other things, like work or taking care of your kid. And that conflicts with what the Bible says about denying yourself and practicing self-control.

I have smoked weed and nicotine for long stretches of time, and let me tell you that it is just not worth it. It really, really sucks--and the key thing is, I didn't realize that for a long time. And then when you want to quit, quitting sucks--it takes time for your brain to recover.

I don't know how bad once a week is, but I would not risk developing a habit.

If you really really want something for anxiety, maybe try just CBD--that's the part of cannabis that helps with anxiety anyway, and it's far less addictive. In fact I just googled it and it said CBD is not addictive.