Getting confused by various methods

I have been practicing meditation for quite a long time now and sadly I haven't entered any jhana(which I want to enter). I think the reason for me not progressing is because I switch between methods of meditation a lot, for example if I'm practicing meditation where I simply see my mind wandering and after a week or so I stop and look for another method, like focusing on nostrils and same happens for a week and then I start to look my muscles moving while breathing(I do that because I think I'm not good at this, maybe another one will work), as a result I don't get anywhere and day by day my faith that meditation is helpful gets less and less. I don't want to do that! But I simply can't get any sort of guarantee that I am practicing right mindfulness. So my questions: > 1) Is this the reason I'm not progressing? Do I have to choose a method and stick to it, when my mind tells me to change? > 2) While doing routine work, do I have to do work while being mindful or stick to my meditation object(nostrils, these days :((()? or being mindful and having focus on meditation object will have same effect?