I think it might be over

[Heartbrokenrn]

Been with my partner 6 years, have a 3 yo DC and I have older ones. Things have been getting worse and worse and today we've done nothing but argue. Sex been a long term issue, originally I wanted it and he didn't really, but now I don't care at all. He said in argument today the reason he didn't want to have sex with me is because I'm not who he thought I was.

We've both said awful things but he says he loves me. Honestly I just think he's scared of what will happen if we split up. We rent and neither can afford to move out the way things are. I am also so ashamed at the thought of another failed relationship.

I know I'm not perfect (mental health issues)but neither is he

I don't know what to do

It’s tough but you need to do what’s right for you. Is it really worth staying in a relationship you’re not happy with just because you’re renting together? I know you have a child together and it’s a lot to decide to end a relationship but you need to think about what you want for your life.
If you want to make it work then is couple counselling an option for you? If you want to make it work then the two of you have some hard conversations to go through. You should agree that they are a chance to be open with each other without it turning into an argument. You will both say things thag might upset the other but you’re doing it to be honest and work on healing your relationship. Explain what you need and want from each other and try get your spark back.

Do you have a good support network around you who you can confide in and who will support you if you decide to end it?

This toxic relationship is only making your mental health worse, I assure you. It's time to end it.

Whilst there are several things to pick up on what did he mean by "He's not who he thought you were?". Almost sounds like you met of a dating app and your pictures were different from how he expected.

Can you tell us what he meant by that? Either way sounds sadly like you guys aren't suited and might just be together for the sake of it. If your relationship is not making you happy it can only be bad for your mental health.

Time to consider if it's worth it

Check that you are getting all the benefits you are owed and look at splitting up.
The atmosphere can’t be good for you or the kids.