So my situation is that I have a switch which controls an outlet. I want to wire in a switch outlet combo to still control that outlet with the switch, but also have constant power to the outlet on the combo receptacle. The issue is that there are only to hot wires in the box. The grounds are wire nutted together, one hot line is independent, and the other is wire nutted to two other hot lines. I have tried every possible combination that I can think of. The switch still works as before but I cannot get power to the outlet on the combo receptacle. How can I wire this so I can get the desired outcome?
Your description and comments are a little confusing, and your picture lacks detail, but I'll take a general swing at this. I think you want to swap this switch for a Leviton style switch/receptacle combo with the new switch controlling the existing receptacle(s).
Add white wire from the existing nutted white wires to the silver screw on the new device.
It looks like the wire from the top of the switch goes unspliced directly into a cable with two insulated conductors, if your existing receptacle is not a split duplex that cable normally would be a cable to the receptacle.
If you want the switch to control only the existing wall receptacle, and the half of the combo to stay hot then attach that top wire to the gold screw and the wire from the bottom of the switch to one of the black screws. There should be two black screws, it doesn't matter which one since you should be able to see they are connected together.
If you want the switch to control both the receptacle at the switch and the existing then attach the top wire to one of the black screws, and the bottom wire to the gold screw.
Add a bare wire to the ground screw.