endometriosis.. was diagnosed. couple weeks ago

okay so i have never in my life weighted over 180 even prego with twin. so in January i started gaining weight and was fatigued all the time and could sleep all the time. to add to this my period was so painful nd heavy i felt like i was dying. i gained 40 lbs between January and april. the begining of april i had finally had enough nd went to my doc. at first she said i was depressed. which ive never been not even baby blues. but i gave her the benifit seeing how i had barried my step dad , 3 aunts and an uncle all in march. but this started in January. needless tp say i hadnt even had a chance to start taking the meds when she called me back to her office and started asking more questions. was sent to see a specialist two days later and diagnosed witha severe case of endometriosis which i was told i have had for years but was missed till now. i have started all the meds. but im still so tired and i cant seem to drop the weight. what do i do? i have always felt uncomfortable with my body till last summer which i work so hard for. now i have all this weight around my tummy. please help. i dropped dairy from my diet. im allergic to avacado, nuts, pineapple, chocolate. i need help dropping this weight and getting back to being me. i have never been depressed before and i dont like this feeling of darkness. anyone dealing with this have any suggestions. and yes the diagnosis is bad enough the doc is talking surgery which i do not want. if i can do this without surgery would be a blessing. so please any help would be. great.