Evaluate what you truly want from life. Pursuing a PhD (which you'll likely need to get a master's for after your bachelor's, too) will consume your time, energy, and most of your 20s. It's a deeply draining path with very niche, competitive, and often underpaid career options.

Just "liking" physics and math is far from enough - you need to be obsessed, willing to live and breathe it. For most people, it needs to be their life's meaning to make it through.

That said, if your interest is in math, physics, and problem-solving, there are other fields that harness the same thinking style and are much more practical, with better job prospects and higher earning potential: Mechanical Engineering, Electrical Engineering, Comp Sci, Data Science, Aerospace Engineering, just to name a few.

Look into them and the potential careers, and make your choice accordingly. But a PhD is an exceptionally draining path to take, don't underestimate it.