Am I an evil stepmom?

Hi Reddit, I hope you can all help me. I (F24) got with my partner (M34) when I was just 20. I knew he already had two kids at that point (B and G age 6 and 8), but made it very clear at the start that I wanted it to be a gradual introduction as to be honest, I had 0 interest in being a step parent when I was 20 and in university. I understood that this might change his decision whether he wants to be with me or not but he decided he was happy with that and stuck with me, even if it meant that his kids will have no relationship with their step mother. As time went on and I finished university, I became more comfortable with seeing them. We moved in together and he has them every other weekend. But the problems started then. My sister lives 6h away from me and is experiencing motherhood with no family around her. I would often go and see her on the weekend that he had the kids, and this became a problem for him. Not because he wanted me to spend time with the kids, but because he “preferred” to get them in my car because I worked hard to buy myself a great car. He doesn’t respect my boundaries. I listened to his concerns and allowed him to use my car every other weekend (which leaves me stuck without a vehicle in a remote area) because I’m not insured on his car. But every time he uses the car, he allows them to absolutely trash the car. One of them literally left a McDonald’s burger, out of the box, on my back seat. When I raised this with him, it was a problem. He said I’m just finding any reason to pick on his kids. This is just one example, things like this have happened all the time. As another example, I couldn’t find my ipad so I asked him where it was and he said he let his son have it for the weekend. When I said this was unfair because he didn’t ask for my permission, he said I was acting like a spoilt brat. What has tipped me over the edge is this weekend. Unfortunately I had a miscarriage. I understand he couldn’t come to the hospital with me because he had both kids (age 9 and 12 now), but he was completely unsupportive. When I was in the hospital he didn’t text me once to see how me and his unborn child were getting on, he just proceeded to tell me that he’s exhausted because he feels like a single dad when he has his kids (two weekends a month) and no support from me. After about 5 hours in the hospital, I finally had a text asking about me, which was “how you getting on?”. I made my own way home and his daughter was lay across one sofa, and his son lay across the other. I was visibly tired, upset, and in pain and I asked “do you mind going on one sofa so I can sit down?”. Again, this was a problem. He took me upstairs and lectured me and said if I keep telling his kids what to do they won’t want to come to him anymore. I had just had a miscarriage and he expected me to sit on the floor. Because there was nowhere else to sit, I lay in bed. I lay there 5 hours and he didn’t come and offer me anything. I text him asking for a cup of tea, and he made one and sent his 12 year old son up stairs to give it to me. He just ran upstairs in excitement now. I was praying he would finally ask about me and see if he needed anything. All he said was “daughter has just lost a tooth, can I borrow some money to put under her pillow?”. Please can I have honest answers. Am I being crazy here? Am I the horrible one or the evil stepmother? Should I be absolutely fine with them trashing my car and making me feel a guest in my own house that I contribute 50% of everything to?

UPDATE: many of you are advising me to leave which I agree with. My problem is, I’m 2 hours away from my parents, tied to a contract in work, tied to a tenancy agreement for 6 months, I don’t have the money for a deposit on my own place because my bills are so high on this house (which he chose for us to live in despite there being cheaper properties in our budget), and I don’t really know anyone at work or have friends in the area because we’ve not been here long. I don’t know what to do or how to get out

Update again: please can somebody help me or advise me. I’m dealing bad with the miscarriage and he’s made me feel guilty about not coming with him to take his kids back (2h there and back) and wanting to go to sleep. He said their stepfather does loads with them and they notice that I don’t do anything. Now he’s home and he’s stomping about the place in a foul mood, making me feel on edge. He said he’s fed up of me being miserable. I’ve tried to explain I’m not miserable I’m just (given the situation) upset, tired, mentally and physically exhausted and feel unsupported. He said I’m toxic and that it’s my fault he reacts in this way. I honestly don’t know what to think I’m starting to feel like I am the problem and I should have gone with him to take the kids regardless of what I feel like.