The foregoing contains some good advice, but is a bit low-key. If the following (this IS a rumour network) causes alarm it is probably to the good.
I would recommend that no-one who has experienced barotrauma should fly without solid advice from an aeromedical expert to establish the underlying cause, treatment and/or medication to be used. Once finding yourself prone to the event, never get airborne without a squirt bottle of suitable medicine.
I think that Beconase and other steroid based drugs are for long term treatment of a chronic condition. Pilots must have medical clearance for their use, and consideration given to the underlying cause. I don’t believe they will be of any use in an acute situation. For that you need a powerful decongestant that liquefies goo and shrinks the nasal/sinus passages. Otrivin may be one of these, but get medical clearance. (not just pharmacist advice) A name from the past is Neo-synephrine which was extensively recommended. Whether that is/was a trade or medicine name, or if still in vogue, I do not know.
These events must not be taken lightly. Ears can be a source of considerable discomfort, perhaps disabling, but maybe self-limiting since the drum will burst and then the pain probably won’t get any worse. But that may not be the end of it; I know a guy who went through that process in a fighter (fortunately a two-seat trainer) but got over it without apparent ill effect – even loss of hearing. Some 23 years later an event of cholesteatoma disease in that ear may have been life threatening. Maybe coincidental, but apparently a typical cause of this growth. (A recent newspaper article stated that this was the disease that killed Oscar Wilde.)
Sinus pain is the most vile event I have known, and could definitely be incapacitating. I have had a very serious scare, coming close to the limit in a single pilot IFR passenger carrying aircraft. What goes up must come down, and once a sinus blocks it is unlikely to clear without major pain, and if it doesn’t, the owner is going to be in a very bad way. You will probably get relief by climbing, squirting decongestant, and descending at an appropriate rate, clearing ears/sinus continually. Which assumes that you have enough fuel, or are not a passenger in a 747 that may not stop for you. Check this with your aeromedical specialist. If you are prone to such blockages then a routine therapeutic squirt at top of descent may help. Have care though, it has been said that excessive use of these medicines can result in them reversing their action and being of no help at all. More words with the Doc.
Flying with a cold will exacerbate any potential problem or produce one for you. Don’t forget that the air entering your head cavities to equalize pressure will carry with it any goo, sludge and infections from the nasal and throat areas. Should such infections blow up in the cavities it is well to remember how complex and delicate the middle ear is, and that the skull is pretty thin around those areas. Therefore get yourself to medical help pronto if you think you are unwell after an ear/sinus event.
Happy flying.