20lb by 23 weeks bad???

I’m really struggling mentally with the weight gain. I didn’t have body issues before in any significant way but I’ve always been conscious of staying within a 3-4lb range my entire adult life. Started out pregnancy around 136 and now I’m at 155. I’m 5’7”. Is this normal? Too much too fast? Ugh I had no idea I’d struggle so much with the weight gain!