Baby fever is strong... but so is my fears

I have 14 month old twin girls and I have had very strong baby fever for the past several months. My husband and I have talked about having another baby or 2 (I have very high chances of having twins again) and we believe we are ready. HOWEVER.... I am nervous this time.

I have PCOS and have had horrible complications for years. I am 5"11 and before I had my girls I was 370, and no issues other than my PCOS. When I was pregnant with girls my weight got to 415. I had major heart issues that had me hospitalized for a few days in my first trimester. In my third trimester I was 7 points from being diagnosed with preeclampsia. I also had some complications after my C-Section which caused me to have daily IVS for 3 weeks starting when I was 2 weeks PP. At my 6 week check up I was still 415lb. I was prescribed water pills and eventually got down to 400lbs. I am now 14 months PP and go between 399-403 depending on the day.

I am much more active than I have been in years. I only eat once or twice a day (don't have much of an appetite), but yet I am not losing weight. I am afraid I will get pregnant again.. gain weight and not lose it. I'm also afraid my heart will go crazy again and I'll have other major complications.

I am only 24 and my husband is 32. Because of my PCOS the older I get the harder it will be to get pregnant. My husband also has health issues that cause fertility issues. I'm nervous to get pregnant but I'm also afraid to wait too long. The only way to lose these fears I have is for me to lose a decent amount of weight, but that is extremely hard for me and will take a lot of time... but yet time I'm not gaurenteed.

Losing weight is something I am striving for so that I can be the best mom I can be. I may be big, but yet I am active and I run around with my kids and do all the things I should and I am not limited... but I know that I need to lose weight because in the future my weight can cause a lot more issues.

I guess I'm just looking for opinions. I'm looking for other stories and maybe some encouragement.

Am I crazy for second guessing myself. For being nervous?