Oh gosh, I am so sorry to hear about your father, mine also passed away suddenly recently, it is really horrible and money stress just makes it worse (my father also left a lot of debts) 
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As to getting on the housing ladder, I wouldn't panic, you are still really really young. So many people don't buy a house until their mid 30s or even older so you have plenty of time, and a good career. Bear in mind also that a lot can change, you may be promoted at work and increase your income, you might meet a partner who can contribute also...
I do understand its hard though, particularly if relatives from the older generation don't understand and think you should be able to buy your 1st home for 2p in a nice area aged 21 like they did and think it's your extravagance/fecklessness that means you can't! I got a lot of this from my MIL who was also constantly 'helpfully' pointing out examples of relatives and friends children who had managed to buy (usually they were high-flying couples in very good careers and/or had the help of significant gifts from parents or inheritances) and sending me links to houses in lovely areas way out of our budget! We got there in the end though, by saving hard, working extra shifts etc. for quite a few years and our first home was not what you would call a 'good home', it was a small flat in a not very lovely area, but we made improvements to it, continued to save hard and were lucky that house prices rose while we were there, so were eventually able to trade up to a small house in a nicer area (MIL still slightly turns her nose up but there you go!)...
If I was in your position I would sit down and make myself a really good budget, using the tools on the MoneyAdvice Service or MoneySavingExpert website, look at your income and your outgoings and see how much you can afford to save each month. I would look into a Help to Buy ISA which can enable you to access government schemes to buy a property with only a 5% deposit - even if you are only able to save a small amount each month every little helps.
Also, although living with a parent rent free or for a low rent is a brilliant way to save, personally for my sanity I needed to move out in my early 20s. I know technically by paying rent (even a low rent on a room in a shared house) you are delaying the day you can afford to buy, but for me it was 100% worth it. It's probably much more achievable to look at saving towards a deposit on a small flat or shared house, or maybe even keyworker accommodation if you are eligible, than trying to save to buy?
Best of luck!