Weight gain

Ten years ago when j had my first baby, it was a stressful situation for my family's nd I gained 100lbs nearly- in that ten years I have sworn I was gonna get it off but never have and I had another baby in the midst 2 years later. In the last year I have successfully lost 50 lbs of the 100 and found out I was pregnant and so excited! Just went to my 12 week appt. and I have gained nearly ten lbs already!!!!!!! I'm overwhelmingly sad about it and wanna cry so bad. I finally am not sick anymore or dizzy- so I worked out again for the first time.... Please tell me I can get back on my game and lose it !!