Persevere. If you are aware of your feelings, you can do something about them, so that's a positive! If you have any negative feelings, try to figure out why that is. Is it that your uncomfortable, or have something that needs to be done or is it that your mind is wandering? If there's something that you have to do, then do it & cone back to meditating later. If you're too hot, cold, hungry then sort that first. If it's that your mind is wandering, then give yourself 10 minutes or so to write it down in a journal. Then try again. If it's that your mind is saying this is pointless, then talk back & say it's Not! Our minds have a habit of putting us off & distracting us from finding peace. If it helps then start with a 10 minute meditation & work up to 30 mins or longer. There's literally thousands of meditations, it's just a case of finding the right one for how you feel in that particular moment. Eg if I stressed, then I'll find one to stop over thinking. If I'm wanting direction & purpose, then I'll listen to one for that. If I'm trying to sleep, or depressed then there's ones for them too.
You've made a Good start, now keep going!
Since I have began meditating I do not find that I have increased irritability. In fact, I often feel more calm and in control of my negative emotions than I previously was. I do find that I am more aware of my emotions. I think I notice when I am beginning to become irritable, sad, angry, etc more quickly than I used to. I also recognize this as an emotion that I have a choice to react to. I don't feel the need to dwell on these emotions as much, I feel them but they don't seem as big and consuming. I also reconize that I can simply shift my focus and that may change me emotion.