It sounds like you might be one of those people who tolerates high doses of substances, like me. I get it. I've found that cycling between different meds – high-dose sema to tirz to reta and back to sema – works best. That way, you always have another option. If you just keep adding more, you'll build up a tolerance to everything and nothing will work. Then what?
Slow down. It's a marathon, not a sprint. Try switching to reta for a while, and expect some weight gain at first. Stick with it for a few months. If you plateau, switch to sema instead of adding more stuff.