I haven't used marijuana in years, but it always took away my depression and any suicidal ideation, even if it made me anxious. Of course, my future also wasn't as bleak back then, so getting high still allowed me to gain a sense of hope. I don't know if that would still be the case today, seeing as my circumstances are much different. It's still illegal where I'm at and I just moved hundreds of miles from anyone I know, so no idea where to get it. I often wonder if it would help now.
But back to your question, who knows? I think for me, it would make it even harder and more scary. It's a pretty unpredictable susbtance for me, which is one of the reasons I stopped using it, but mainly because of a job that did random saliva drug tests (so you could technically still smoke and not get caught if you timed it out right). Sometimes it makes me incredibly anxious, making something like that harder. Other times, it brings me more hope and solace, also making me not want to jump, but everyone reacts differently to it. I think you would know how you'd react more than anyone here.