I started insulin last Monday. Slow release Triseba on its own for 4 days, but was having big spikes after meals, so I've been on 2x Fiasp (fast acting) before lunch and dinner since then. I expect I will be increasing the dose of both in the next few days as I'm still a bit high in morning and bedtime, and still have spikes after meals including breakfast, so potentially another Fiasp and higher doses of everything.
So I suppose you ought not to worry about still being high for the time being - I guess its safest to take things slow at the beginng!