Trekking Bars .. Ala Figure 8 bend.. more hand-hold locations, still use the flat bar controls..
Once tried the northroad variety, they made the bike pretty twitchy,
could be the weight shift off the front wheel, & an already light front end..
you are just not putting the weight on the front wheel, so maybe the bars need a longer stem..
Or fit a newsboy basket & carry more stuff in it, should fix that.
or front Panniers, porteur rack, etc.