Help!! 08 mazda3

Started about 2 weeks ago, I went to start and it acts like it wants too but won't fire up. My brother came and pumped the gas a few times and it cranked right up. And has been fine since until yesterday I went to leave and it took about 3 tries to crank up. Then I got to store and went to leave and it hesitated but started then stalled so I gave it some gas after starting it again, then this morning I went to leave and it will not start at all.... It just keeps trying to turn over. I just replaced the battery 1month or so ago. I have a video but I'm not sure how to upload it :(