I know it's coming to an end but why am I so upset?!

[moneymoneymoneyohdear]

4 years together
No dcs
Everything has just gone wrong lately and I think the end is inevitable
We're both unhappy
But the end scares me and makes me stupidly sad

I am so so fed up

Sorry for the delay, OP.
Difficult to know without knowing him but here's my input -
1 Don't spring the conversation on him from nowhere. Surprise won't help you.
2 Perhaps preface with "we need to talk about our relationship; is now / X o'clock a good time?"
3 Don't start at all if he's fully engaged in another activity, even if it's 'only' watching sport. You need his full attention.
4 Choose your location carefully- home, garden, country walk, quiet pub, whatever makes you feel safe
5 Have a plan of what you want to say; what's your main message? Make sure you have an exit strategy for the conversation, esp if it risks gets too heated.
6 Worse case, have a plan B for where you could stay tonight, preferably with someone to talk to.

Good luck

PS When I split with my husband, I started with "I'm not happy" and went on from there. The 90s (80s?) Book "Feel the fear & do it anyway" was always my inspiration!

He's being nice now, but still nothing is done around the house.

Says he will but nothing happens...........

Well tell him that actions speak louder than words!!
And maybe start to get a plan B for yourself.

Ask for a time to sit down and discuss ALL chores that need doing, how often etc. and how are they going to be split. You also hand over responsibility for them being doing and yes remind him actions speak so much louder than words.