Awww hun don't stress- you are growing a beautiful gorgeous baby and there is alot going on in there. Im 5'1 was overweight at 65 to being with and nearly died when I hit 80 when I was pg. I lost it all fairly quickly though but given your height, your weight sounds like its spot on track to me. I found I gained the most in the first 2 trimesters, and less in the 3rd and my key tip is- stop weighing yourself.
Look in the mirror- have a look at that gorgeous growing belly and picture that little beautiful baby getting all the nutrition and padding it needs to grow up strong.