Hi Peppa,
I am a make up artist so might be able to help with a gentle nudge. firstly whatever you do don't plaster yourself with a ton of make up and think it will make you look younger, maybe in a photo yes it will, but for everyday life it will not.
Most people do not look after their body well enough and most fall down on liquid intake. do you drink enough water a day? Not tea, coffe, wine.. but water (poss wth a bit of juice to help) if it is under 2 litres a day the you need to start making that your goal. It will not bloat you, it will help your body clean out toxins and help your skin be more hydrated and respond better.
The next thing to look at is what you eat. Do you manage your 5 a day? If not start now. Ditch any junk food, best of all try a healthy detox which again will help your system restart and clear out toxins, you will end up a bit slimmer, but also your skin, hair and nails will look fab. Do you take a good daily multi vitamin?
Next is a good skin care routine. No particular make to bandy here. Don't be sucked in by crazy promises. An anti aging cream only has to have sunscreen in it to legally be classified as anti ageing, all the rest is mostly hokum. Find a routine within your budget, that you like the smell texture and feel of and use it religiously. cleanse, tone and moisturise... after a few weeks if you do the rest too your skin will be feeling much better.
Lastly go and get a nice haircut. If you are brave enough find a salon with someone you can really trust and discuss with them how you feel and that you need a change. Get some pics together of looks you like and leave yourself in their hands. a touch of colour may help, a new style or just to feel the smartness of a fresh cut.
HTH a bit, good luck x x