The grade (incline) is what is creating most of the discomfort for the OP. on a flat section, this is a non issue because from a standing start, I'd bet he can get up to reasonable speed pretty quickly. on a hill, not so much.

Aside from looking for an alternate route to get up that hill, taking the center lane is the safest, IMO. Be prepared to smile & wave at some angry motorists who are upset with "another d-bag cyclist" however ... ..