Real Life: Impossible Potty Training!

Well, my youngest son is 2 1/2 and I have been trying and trying to get him potty trained! I would say at least 3-4 months now! He does so good if I let him run around naked but the second I put underwear and pants on him he wets himself! Sometimes he will even do a #2 in his pants! I have tried the sticker chart, toy rewards, candy rewards, etc. and he just don't seem to care! He is not afraid of the potty or anything so Idk what is going on! My 5 year old potty trained pretty easy! I just let him run around the house naked for about 2 weeks and that was it! I was a stay at home mom at that time though! I feel like if I didnt have to work I would be able to work with him more but I don't have that choice right now! I guess all I can do is hope he will get it down pretty soon here! Until then we will go through 5 pairs of underwear a day!