Mum thumb/mum wrist (de quervain tendonitis)

[Quadrilingual]

I've been diagnosed with De Quervain tenosynovitis on my left hand. The base of my thumb and side of my wrist hurt. The doctor said to wear a support splint all day and to put anti inflammatory gels on it 3 times a day and to have painkillers.
I was then advised against pharmacist to put anti inflammatory gel on it since I am still breastfeeding. (Baby is 8 months so doesn't use as sole food but still bfs).
So I've been wearing just the splint and taking some painkillers.
However I've noticed that the pain is worse when I'm wearing the splint during the day and then once I take it off it feels better! Is this normal??
Anyone else had this and how did it heal and how long? What helped?
Here is my hand with splint.

Photo

I had this a while back. I didn’t have a splint like that though. The splint I had had a bent metal bar on the palm side which prevented me from bending my wrist. It held my thumb against my hand, as any temptation to use my thumb resulted in excruciating pain. I was prescribed Naproxen and omeprazole. I also saw a muscular skeletal therapist who gave me lots of exercises. It took about 3 months before my thumb was useable again.