No, YDNBU - it’s totally possible to make a big difference in 10 months!
Key is to find stuff that works for you and stay as consistent as you can - if you have a wobble or a treaty weekend, don’t throw your hands up, just start again the next day and keep at it.
Exercise is really important, but 90% of it is about what you eat. Obvs you need to get rid of junk - empty calories in stuff like fizzy drinks, all sugary sweet stuff, crisps, fatty fried foods - and try to limit alcohol etc. For me, cutting down carbs is always the thing that makes an immediate difference. I dump almost all bread, pasta, rice, potatoes. For meals where I have any of that stuff, it’s always brown/wholemeal, small portion. And Zero noodles are brilliant!
I just have a nice piece of meat or fish and double up on veg and salad - there’s loads of lovely recipes, and you can have unlimited amounts. Maybe with some beans or grains. Always have a nice dressing, mayo, etc. Including healthy fats is important - olive oil, avocados, nuts, full fat Greek yoghurt with berries - as they help fill you up and absorb certain vitamins. Drink loads of water, or fizzy with a bit of lime or lemon.
Intermittent fasting is also helpful if it suits you. I don’t like the 5:2 thing, but I’ll often try to leave at least 12 hrs between my evening meal and breakfast/brunch next day. Doesn’t suit everyone though. And def don’t bother with any low fat or diet products - they’re shite and usually full of sugar.
With exercise, I’d start Pilates with a good teacher ASAP - great for increasing core strength, improving posture, balance & flexibility and giving you long, lean muscle. Stuff like Zumba is fun if you like a class, and when you’re ready add in some HIIT to help you burn fat and tone up (would recommend doing a class until you’re confident with shape & form & not going to hurt yourself, then there’s loads of excellent free stuff on YouTube).
Good luck - I really hope you have a lovely time in Spain!