I am 25 years old and engaged to marry my boyfriend (35) of 4 years who is divorced and has two children (ages 10 and 5). Once we got engaged I began having panic attacks about being a stepmother. I have my own step parents whom I don't have good relationships with because they have been unhealthy partners for each of my parents (obviously I am not treating my partner or his kids badly, but it has created a sour image in my head about the image of stepparents to children). When my boyfriend and I started dating his kids weren't really in the picture. I didn't spend time with him when he had his kids at his house, and we would spend time alone on his "off" days. It was only when we moved in together (2 years into our relationship) that I became involved with his kids. In the beginning we slept separately so he could continue sleeping with his kids like he did when they went to his house. We didn't hold hands, say "I love you", etc. At first I was supportive of this because I wanted to ease into my relationship with them as well, but it was difficult too because when we were alone we had such fun and romance and interaction, and when the kids came it centered around protecting their feelings and being in hiding. Also, when he moved in with me his ex-wife began to "renew" her feelings for him and began sending messages and writing love letters, etc. She decided to hate me and she let her feelings be known to her 10 year old daughter. This was a difficult time because my boyfriend didn't return any feelings but he didn't stop her from expressing hers either out of concern that he would see his kids less. Initially, I thought it would be great for them to be friends for his kids (being a child of divorced parents myself) but wound up hurt when I was excluded for them to spend time togethr and found that this propelled his kids' image of mom and dad getting back together. As time progressed, my relationship with the 10 year old got more complicated when she denied me being her dad's girlfriend, introduced her friends to me as her dad's "friend", didn't even come inside the house while she waited for her mom to pick her up if it was just she and I alone, etc. In November of last year things started to turn around when my boyfriend started to take more action to express his commitment to me. He talked with his kids, told his ex wife he wanted to marry me and start a family with me, etc. The 10 year old changed her attitude somewhat but mostly stuck to small talk (hi, bye, how are you, forced hugs, etc.). Then in January, the ex-wife got a boyfriend and I really noticed a change in her behavior (less texts for small talk, more distance between them, etc.). She even emailed me and told me that she had told her 10 year old that "she doesn't have to hate me". In our home, I have really assumed the role of the mother, and I am kind of resentful that I am always doing their cooking, getting their uniforms put together, but they could care less if I am there or not there, and CONSTANTLY talk about their mom, and their mom and dad being together. My boyfriend really doesn't pick up on why that would be annoying, and it frustrates me even more. I feel very underappreciated by all of them. His family has a very close relationship still with his ex-wife and this is also hard for me. I feel like I am always competing with someone who should be in the past. For the most part, I have a great relationship with his kids, especially the 5 year old. They don't yell at me, or cause tantrums or anything like that. They know that we are engaged and didn't put up a fight. They are genuinely good kids. But without kids of my own, its hard for me to not take some things personally, especially with the 10 year old. I can tell she is still grappling with our relationship, and I want to be understanding, but it also drives me crazy wondering for how long this will continue, especially since she will be a teenager in a few years! I spend more than half the week with them, and their dad is usually working, but she still prefers an aunt that she sees once a year, or a friend than me. She obviously sees me as a threat or something, but its hard to not be hurt when I do everything for them and they don't really genuinely love me or would be more than happy to have mom and dad back together in a hearbeat. Lately she also just blatantly ignores me, or excludes me. I also have a lot of issues about things in the future... That my kids will not be his firt kids, that my finances will go to support his kids, that the ex-wife will always be in the picture, if they will ever stop talking about their mom and dad being together, if my kids will be subjected to hearing about their mom constantly, if my kids will get less attention, if I will ever be as close to his family when they still constantly communicate with his ex, how we will be able to support 4-5 children, etc.

To be honest, I am scared about being a stepmom and its not what I envisioned for my life. Unfortunately, many, if not all, of my issues with my boyfriend revolve around his kids, his relationship with his ex because of his kids, his family's relationship with his ex because of his kids, our unability to travel or move because of his kids, finances because of his kids, etc. And its difficult to talk to him about any of it objectively because of course he loves them very much and he doesn't understand. I don't know how to handle a teenager in a few short years when I will just be beginning to think about my own family.

Am I being too over-analytical? Is there a way that I can work through these issues since most of them stem from my own doubts, and hypothetical insecurities? Is there a better way to communicate with my partner about these things?

I would really appreciate some advice (pros/cons) from people in a similar situation or who went through a similar situation. Thank you.