Had Keflex before and got no side effects at all, Im paraplegic ...

Had Keflex before and got no side effects at all, Im paraplegic and suffer from UTI's quite a lot, i am also allergic to penicillin. Got given keflex 2 days ago for another uti and this time round i am doing nothing but sleep, I can manage 9 hours awake before i start getting the head drop tiredness. I was given cefaclor last time too, only manage to take 1 of them (250mg) and i got some massive head dizzy spells and random arm twitching, that's when they was changed to keflex (500mg x3td) which im taking now. No belly pains, well i felt as tho i was all stiff and rigid the first day i started the pills but the day after i was fine no pain at all, just the awful tiredness. I shall cope with it tho as I want rid of this foul smelling urine.