The suffix -taas is what you're looking for to make a present participle. For example, viintaas tuz would be "a shining blade."

That's for making adjectives, mostly. Progressive tense is pretty rare in the dragon language, so your examples would be more commonly expressed like "this headache kills me" or "why do you jump?" Another way you can express it, if you have to, is with using los 'is'. Mu los krif would be "we are fighting," but it'd be much more typical to say mu krif "we fight."

Paarthie, is there a complete list of affixes? the pinned post seems to be incomplete.