@Tanazanite Two suggestions:
The way the current translation is worded makes it seem like he's neither her boyfriend nor her osananajimi/childhood friend.
[ul]
[li]
Even if I'm not her boyfriend,/ even if I'm just a childhood friend. (parallel structure and repetition to get his desperation across) or[/li]
[li]
I don't care if I'm not her boyfriend.../ ...and just a childhood friend. or[/li]
[li]
Even if I'm not her boyfriend.../...and just a childhood friend.[/li]
[/ul]
I'm doting on you too less, rather.
I'd say/think/etc I'm doting on you
way too little. (Mirrors Umi's line about being doted on too much.)