I'm not too sure how to properly start this or if it's gonna make sense or whatever but here we go...

I'm a 23 year old female, I've been with my now 29 year old boyfriend for almost 18 months, in that time he's kissed/flirted/sexted a coworker and lied to me about it, I found out and he deleted all her contact information from his phone/tablet etc and yes, I stayed with him and things seemed to be going good, or so I though, a few days after my birthday and a few days before our anniversary, I found out he was back in contact with her(on Snapchat, which was the same way as before) and had been for a few weeks, obviously lying to me about it, I saw some of the messages he'd sent her and he was speaking to her/treating her like he should have been me...he's never treated me like that or spoke to me like it, he always told me he didnt compliment me because he always found it difficult in a relationship but was giving her ones left, right and centre, and you guessed it....I gave him another chance...but all his friends were told what a scumbag he had been and he's been forced to delete Snapchat completely(he has no other social media accounts)
Through all of this, I was staying at his, looking after and feeding his two dogs and making sure there's a cooked meal when he got in from work, as well as getting him groceries etc

it's 5 months since then and anytime I've brought it up or had insecurities about it(I will say now that I suffer from quite bad anxiety, depression and low self esteem), he's since told me that me in lingerie doesn't excite him and he still never gives me compliments and any time I have cripling insecurities/worries etc due to my axiety, he makes things worse by giving out or telling me to 'stop it' or to 'stop overreacting' or gets annoyed if I get upset etc(which for anyone who has anxiety, is possibly the worst thing to do) because it makes me second guess myself and not want to tell him things in case he reacts like that

I'm a large woman(UK22), which he has always says doesn't bother him in any way, yet I've also found him looking up ways to get me to lose weight and he's pretty much/indirectly told me he would rather watch porn than have sex with me, which has made me stop/severely reduce eating multiple times for an extended period of time

Our sex life is also getting worse as I'm not 'cumming' evey time during penetration and he's starting to get really pissed off about it which is stressing me out and upsetting me which is definitely not helping things, he'll mention it every time it happens, I tried to make suggestions, that if they didn't work we'd try something else but he then started twisting my words and putting words in my mouth etc and that's now adding even more strain to the relationship

This may seem completely stupid to some people but to me, and hopefully to others, it's incredibly serious, I've cried myself to sleep...and burst into tears when he's left a room many times and I constantly ask myself why I stay, I constantly doubt myself and ask myself if I'm just being stupid
I love this man with all my heart despite everything that's happened...but he doesn't love me and he has told me that.

I need advice..or if there's anyone else in a similar situation, how do you do it?

I do apologise for this being so long and probably tedious but that's my story/problems

Thank you for reading!