I don't know how to carry on like this

[NoUseNumber31]

I have a 4 year old Ds, he is gorgeous and loving but the tantrums are extreme. He is so clingy with me when I am at home, he hangs off me like a monkey and if he doesn't get his own way he will scream and scream and scream.
I have other children too and work and I'm at the end of my tether. I've spoken to the health visitor, the nurse and his pre school and they have said they think he will grown out of it but this has been ongoing for a year at least now.
I know people have it harder but I'm really struggling, he starts school soon and he is nowhere near ready for it.
Please tell me I'm not alone!

That sounds really, really intense. Where does he go when you're at work?

He goes to pre school, he sometimes get a little bit upset when I drop him off with my dd but he loves it when he's there.
I don't get home from work until he's in bed and he rarely asks for me unless he's upset about something else but when I'm home it's a totally different story.
I so look forward to my days off with him and his siblings but I end up so touched out and frustrated then snappy. Then I just feel awful for being snappy! It feels never ending at the moment.
Thank you for your reply!