You’re still on a low dose of lamictal so I think you should wait to see if your pdoc wants to raise the dose before thinking of adding an additional drug. These are powerful drugs so be cautious. You said you are drug sensitive anyway.
I get really frustrated that people dont use vigorous exercise and getting out more to fight depression. It sure helps me. My pdoc and I were laughing the other day about people expecting to find the magic bullet, the drug combination that solves everything. But yes, getting the right combination is important. Today they do sometimes use more than one stabilizer but everyone’s different.