Growth on one side of septum piercing. Can someone please help?

It should be fully healed by now and not getting any crusties.  What are you doing to take care of it?  First, stop pushing your nose like this.  Moving your nose and the jewelry more than necessary will cause irritation, and irritation causes irritation bumps and keloids.  Only touch the piercing when you are cleaning it or blowing your nose.  If your nose is a bit runny from allergies take an allergy medication so your nose doesn't drip all day, wiping drips moves the jewelry a ton and if you do that all day you are causing so much irritation.

I know how difficult it is to stop touching your septum, I have one too, and I also have a keloid on it because I touched it all the time.  Stop touching it.  Only touch the piercing when you are cleaning it. 

You should clean this piercing twice a day with sterile saline wound wash spray and sterile gauze pads.  You can find both of these at walmart, even with the current pandemic going on.  Saturate a sterile gauze pad with the sterile saline spray, and hold the gauze on both sides of the piercing.  Lean over the sink or a washcloth or something so it drips on that instead of all over your face.  Soak the piercing like this for 5 - 10 mins.  After soaking, use the same gauze pad to gently remove the softened crusties.  You never want to remove them when they are dry, unless they fall off on their own.  You want to soak them off and remove them gently so they don't cause damage to the skin around the piercing.  Soak your piercing like this twice a day.  I would do this for at least a month, and baby your piercing for that time and give it a chance to heal.  Mine took about 7 months to fully heal, even though they usually take 4 - 6 months to fully heal.  I didn't take care of mine correctly which is why I have a keloid on it now.  Give your piercing the time it needs to heal 100%, because right now its at 95% and it won't ever fully heal until you give it what it needs.

It's hard to tell from the pic but it's either infected or it's a scab.The crusties you describe is a scab trying to heal and you need to leave it alone until it falls off on it's own.If you keep taking it off another one will form since it's not fully healed yet and you risk getting it infected.if there's pus coming out then you need to see a doctor for antibiotics.

Well, you might google up some pictures of old people with gross noses and wonder how it happened to them.  Now you know.   Doing really dumb things does have its ramifications.