Been through similar experience with my son last year who sounds a lot like yours. Difference being he likes the university location and wanted to go back after Christmas but felt a failure as he hadn't made any friends and found doing shopping, cooking, laundry etc overwhelming combined with university life.
He went back last year but was overwhelmed again after just a few weeks, we had a family bereavement and serious illness in another family member so it was a busy and stressful time.
Things went down hill from there but he refused to come home as that was giving up, he thought. A fellow student in his halls killed himself.
He was barely eating as too difficult to face people in his shared kitchen or get out of bed to go shopping. I thought he was depressed, he stopped communicating with everyone including university. We went to see him as very worried, he was able to say he had some suicidal thoughts but still refused to come home.
He completed the year with some help from student services and counseling, refused to see Doctor until end of year, diagnosed with anxiety and depression, on anti depressants still.
It was a very hard time for all of us, I had to get student services to check on him several times, I was very worried about suicide risk after reading advice on various student websites.
You know your son best, talking with him in a comfortable way, maybe on a walk so doesn't feel trapped or have to look at you while talking, will help you check if it's a wobble or something more serious.
Encourage him to contact Student Services for help and talk to finance people about the financial implications if he takes the rest of the year out. Taking the time out might help him decide what he wants to do and isn't as final as dropping out.
Sorry this has been a bit long but I wanted to reassure you that it's very common but should be taken seriously as student suicide rates are increasing and boys/men are more likely to be successful and less likely to seek help or talk to someone when they feel like this.
It's great that your son has been able to talk to you, give him lots of praise for that.
We also keep telling our son that whatever he wants to do, we will be there to support him and he always has options, no degree is worth being miserable for years or causing mental health issues.