at level 1 I get two spells to last a whole day

This is going to get better at higher levels, but will never not be an issue. Full-casters need to be able to make the most of their higher-level spell slots and still be able to function with their lower-level spell slots. Mid-casters like yourself need to be able to function without spells, and make sure the spells they do cast count.

I’ve already re-adjusted my character to care less about casting spells because it seems I’ll hardly get the chance to do it!

All the more reason to make sure your spells have an impact when you do cast them. That’s not to say it should never be cast just to deal more damage, but it does mean you should be asking yourself what spell would have the most impact and also when to cast it to have the most impact.

Also I don’t seem to have any damaging touch-range cantrips, is that a deliberate decision because they’d be too good for spell combat + spellstrike?

I’m not sure about that. The basic arcane cantrip list predates the Magus (by a lot, considering it was based mostly on the 3.5e DnD cantrips), so spellstrike and spell combat were certainly not considerations when putting that list together. Considering those cantrips were designed for use by low-level sorcerers and wizards, I believe the designers probably just thought no-one would ever use a touch-range cantrip to deal a bit of damage.

Where it comes to the magus, a damage-dealing cantrip would only be a little bit of extra damage for you. Nice, but the main benefit comes from having a touch-ranged cantrip at all, no matter what its effect. Arcane mark fits the bill, allowing you to make that extra attack without expending a spell slot.