That's an interesting suspicion about loratadine - will bear that in mind in the future when recommending antihistamines.

The two other oral non-drowsy antihistamines available here (non pseudoephedrine based) are fexofenadine (Allegra) and certirazine (Zyrtec) - I believe that these both require a prescription in the States and can be quite expensive but from what I can see on online pharmacy sites, there seem to be generic versions available that aren't too dear. Fexofenadine doesn't have any CNS/psych side effects listed and doesn't have the "10% likelihood of drowsiness" that Zyrtec does.

The other options are local treatments - a steroid nasal spray (eg. budesonide, fluticasone, triamcinolone are all available over the counter as nasal sprays here, with stronger versions available on prescriptions) and/or antihistamine eye drops (eg. levocabastine, pheniramine) can help significantly with symptoms and are far less likely to cause either interactions with your medications or any psych side effects.

I think the regulations are a bit tighter on these drugs in the US (probably because we have such high allergy rates in Australia that doctors would spend their whole lives writing scripts for these things!) so you'd probably need a prescription for most of them but there are definitely lots more options to try.