You poor thing - this sounds incredibly tough. I had similar with my first in terms of allergies, and I found it really affected me mentally - but not to the extent it does to you. You poor thing :(
I can only offer practical help with the allergies. If you can get support with those, it might have a knock on affect with easing the depression perhaps? Or at least give you space to breathe.
Food - he’s only seven months and doesn’t need to be depdendent on solids totally just yet. I would ease off offering him anything until he’s more settled. Maybe around 8 months you could offer him plain vegetables - steamed carrots and broccoli, cauliflower and varieties of potatoes. All “safe” things. You could make a very simple soup or offer him potatoe wedge - big chunky things that he’ll love handling and you’ll feel happy about him having.
The hospital - has he definitely had things confirmed? Did they not offer any anti histamine to help things settle down? If not - can you transfer his care to another hospital? I had to fight for a referral after kissing my DS at four months after I’d had peanuts. His skin blistered off and they still didn’t refer me. We paid for a one off private appointment- and when I went back to my doctor, he finally referred me. But the first hospital were crap and I was in pieces, struggling with coping with it. I rang another hospital and asked to transfer his allergy care to them and they agreed. Luckily that was the Evelina clinic at Guys and St Thomas - who have an amazing allergy clinic. They prescribed daily anti histamine to DS - who was five months - for a month to help settle the initial reaction.
Having that really helped with sleep and helped me mentally. Please look into it.
Breastfeeding - a lot of my DS reaction was coming through my milk. I cut out a lot of stuff. I know there’s not a lot of evidence to show anything comes through milk but my DS’s skin was horrendous for months until I did. My DS was prescribed Fucibet initially because he had developed a bacterial skin infection from all the scratching so that needed clearing up.
Scratch sleeves were a god send for sleeping and stopping itching.
As was propolis bee cream to help with the horrendous eczema.
From about one years old, I would buy 1% steroid cream to deal with break outs. It’s not advised for young children but I reached a point where I felt I had to take things into my own hands. Daily moisturiser and steroid cream for breakouts managed his eczema. I would tel the chemist it was for me and I am not remotely regretful because my actual GP was useless and I felt the risk was worth the pay off.
Finally - it will pass. It will. My DS is six now and he still has the same allergies but his skin has been beautiful since he was about two years old. At one point we couldn’t even put him in the bath without having to hold his hands - because he would just claw at his skin. He really did just begin to grow out of it. It just happened and though I put a lot of effort into managing his eczema, it also simply just lessened.
If you can - consider changing doctors/ your son’s care. You need support and you need proactive help in managing the allergies. You don’t have to accept the level of care you’ve been getting.