It is true that the sounds are somewhat similar. They might confuse us, so we must take take great care with the words WANT and WON'T.
Won't is a contraction. Their usage can be very distracting. That is why it can be a great benefit to students of English, to use the expanded form, WILL NOT (GO) instead of
WANT, employs the rarely taught SCHWA sound. The diacritical mark which shows this sound in a dictionary is an upside down letter "e". The sound it makes is "uh" and the same sound appears in words like BUT, HUT, LUCK, DUCK, etc.
Thus, if one uses phrasing like, "I WILL NOT GO." all confusions with WANT can be eliminated.