Before you decide on anything, I recommend that you wait until all the swelling goes down. It's only been 3 weeks and you are certainly in the early stages of the healing process. The healing period can be stressful and it's important to be patient. Be sure to continue to follow up with your surgeon.
It is very soon to see the final result from the surgery, the swelling makes the lips look longer, besides the upper lip make look longer because some of the caudal septum has been removed, making the upper lip look longer, but this does not mean is bad, as once the swelling is gone and the upper lip moves better, then you may recover the shape on the filtrum.
Dear EleanorYou are in the early recovery period and your tip is likely still stiff and firm. Give it some time and likely it will be better in 4-6 weeks. If not better then can look at injectables or surgery as an option. Look for an experienced and well trained Plastic surgeon, certified by the American Board of Plastic surgery. see more than one consultation and make a well informed decision.
Don't worry. It still way too early to worry about any permanent changes o your upper lip and philtrum. It's very likely that the changes to your lip are simply due to swelling and that you will have your old lip back within a few months.The recovery from a rhinoplasty is a marathon not a sprint. At this point I wouldn't worry about a solution to the problem as it's really likely that once things have settled down there will be nothing to worry about. Good luck.