As you've found out most folks want to shave every ounce from their carry piece untill they fire it. Then they wish it was 2 pounds. I'm guilty myself. Haveing tried it both ways, my personal feeling is that it's easier to deal with the extra 3-8 oz in the pocket/ holster and have the recoil absorbtion when I practice /ever need it. ( Too much recoil does impact MY accuracy and enjoyment /frequency of practice .) FWIW, if your only going to shoot 38's anyway, I'd suggest you look at a "happy medium" pre (96') 19-20 oz J mag frame mod 60/36/640/49/649 etc. They are more controlable /comfortable to shoot and are even a little smaller in frame size. I also own and can recommend the newer J mag framed 640's (357)/ 60. Same size as what you have but MUCH more pleasent to shoot due to their 23 oz weight. +P's are no problem in the new 640/60's and I've even ventured some 357's from time to time. Several of these models come/came in a 3" length. I'd note that while a 686 is a fine weapon, it's well over twice the weight (and size) of your 642. You may find you've swung to far the other way. Other in between revolvers that I ( own )and find comfortable to shoot but still easily concealed would be the Ruger SP101 ( 25 oz in 3") .Finally ,any one of the S&W K frames in 2,2.5" or 3"that are unlugged ( 10,13,19,65,64,66) will weigh in in the 29-32 oz range.
Lastly, The only other suggestion I could make ( other than to trade it) would be to put some larger , heavier rubber grips on the 642. I have found the hogue style do help on this size weight gun.
hth