Headlight issue

[Colemantrans]

Hello so I have a 95 GMC Jimmy 4.3L 4x4 - I have no headlights now. When I hit the headlight switch all I get is marker lights and running lights. I replaced all 4 bulbs 2 months ago, so I know that is not the issue. Headlights worked good up till last night. parked car for a hour then came back out to go home and now no headlights at all. When the headlights are on and hit the hi beams the headlights went out, but when you disengaged the hi beams the headlights came back on. Been this way for a while, but never had a issue where the headlight wont come on at all. If I have marker, and running lights could this be a fuse problem, relay problem? Could the hi beam switch on the steering column cause this issue? Please help!!!