You will get good advice from many people on here; you might also find the Debt-Free Wannabe forum on the moneysavingexpert.com website very useful. I think someone else already mentioned the site and it's a mine of, well, money saving tips. People regularly post what they call their "statement of accounts" to that forum and others, who've usually been there themselves, suggest ways to help you dig yourself out of what might feel like a pit.
Years ago when I and one of my exes parted, leaving me in a lot of debt, their advice was invaluable. At one point I owed £15K and I didn't think I was ever going to be back in the black, but I managed it. It wasn't quick and it wasn't easy, but I kept going. One of the things that was slowly throttling me, for instance, was that the bank had kept getting me to consolidate, so the interest rates on the loans and credit cards I had were horrendous. On paper I too had a decent take-home salary, but over £400 a month was going on paying off the loan I'd taken out just to survive when I got left high and dry by the ex. And for various reasons I moved rentals a lot, which always cost at least £1,000 up front. Moving to cards with lower interest rates, and eventually to ones with 0% interest for a limited period, really helped, as did keeping a spending diary where I recorded every penny. And I mean, every penny.
Off the top of my head - as someone else has said, do you need the size or style of car you have? Would the lease company let you trade it in for a smaller or more economical model? By the same token, if you were driving a smaller car, it might be that the insurance would go down; if you absolutely have to have that car, then can you look at insurance costs? Compare the market, gocompare, and several other comparison websites can really help give you an idea.
I know there are a few companies that don't use those sites, and I have found, every year, when renewal time rolls around, we do have to use all of the sites to see who's going to give the best deal. When it comes to filling up your car, if you register with www.petrolprices.com you'll be able to find out where the cheapest garages are in your locality. It's free to register and they don't bombard you with spammy messages (unless things have changed since I used to use them). I know it might only seem like a few pence per litre but it does add up. And we're always using vouchers in this household and any discounts we can find - when I'm preparing our weekly shop I usually check on mysupermarket.co.uk which does a comparison across all the main supermarkets of your basket so you can see what's on offer. For things like sugar and pasta we buy in bulk and decant, wherever we can, and our slow cooker and blender are definitely our best friends when it comes to making meals. I used to leave my debit card at home when I went to work and only take a tiny amount with me in case of emergencies, and I always used to take in lunch. As things got easier I'd sometimes treat myself to a bought lunch on a Friday and we had a kitty for coffee and tea.
The same applies to your household bills. Can you see if moving to another supplier would help? Are there any electrical appliances that use a lot of power that you could cut back on? And I'm presuming you're claiming the single person's council tax allowance.
You say you enjoy food but also that socialising is a bit tricky - are there any cooking clubs or dining clubs near you? That way you would be quite likely to meet people who also enjoy a good meal, and socialising at the same time. Or book groups, or yoga classes, or gentle walking groups - Meetup can be a great site to have a look at, wherever you are. People get up to all sorts!
Or there are loads of voluntary things you can help with - you'd be surprised, probably - ask at your local library if they can point you in the direction of the volunteer bureau for your area or just Google. Where I live there are all kinds of things, from working in charity shops (not necessarily on the till) to museum and library work, befriending, hospital radio, choirs, church groups...that's just off the top of my head. And most local hospitals have a volunteers' department and again, people help with all kinds of things - befriending, photocopying, League of Friends (or fiends as one boss used to affectionately describe it). I used to do a lot of evening classes and in my time I've done everything from desktop publishing to belly dancing (that was great fun, and you definitely don't have to be a sylph to do that form of dance, since I'm not, quite the opposite in fact). I met many of my friends that way, or through volunteering.
Oh, and 38 really isn't old to start a family these days, though it might have been once. There are many people well into their 40s who start families now, although some risks may increase. One of my cousins didn't have her little boy until she was over 40, and I worked with someone who didn't get married and have her daughter until she was about 42 or 43. Another friend and her husband adopted in their 40s.
Good luck - and please, take it from someone who thought she'd never get rid of that minus sign in front of her bank balance, or find a happy life again after splitting up with the aforesaid evil ex, you've got lots of lovely, interesting years ahead of you. 