I've had a really up and down week so some days I haven't been able to eat enough and then some days I've had too much to eat. Not a planned thing just the way it panned out.
On the days your struggle to eat the calories, you can boost them up with things like fruit juice, nuts etc. I really would make sure you're not regularly going down to 1000, that really is low for a man.
I dread going to gym

I'm doing all my excercise on a treadmill at home, maybe I should go to gym to do weights.
And is it better to do weights then cardio or cardio then weights or does it make no difference which order?
What you do really is up to you and what you're used to. Personally, I probably wouldn't recommend 6 days in a row with one rest day. Even my hardcore super fit gym freak friend doesn't do that. He does Mon-Fri in the gym, weekends off. Or I know people who have Thurs and Sun as their rest days, so it's 3 days on, 1 day off. Personally, I can't even do that, 3-4 times a weeks is about my limit, but that's me. You have to find what works for you, no-one here can say do exactly this and that'll bring you the best results because you're you. But personally I would say don't do too much too fast if before you did nothing, build it all up.
I would say you really do need to do weights though. It's not about making yourself all built and muscley, lots of people do them without the intention of getting the bodybuilder look and never do get that. It's just about building up muscles and toning your body. Increased muscle means increased metabolism which is obviously good. I would just say that make sure you've eaten before your workouts, don't just think oh I'll not eat til later and then it'll have more reserved fat to burn off, again it doesn't work that way, you'll just be more prone to muscle loss. I always try and eat a couple of hours before I go to the gym and then a couple of hours after with some protein-y. It doesn't have to be anything massive, an egg white omelette or something would do just fine.
Personally, I'd say do weights and then cardio. If you go all out on a serious cardio workout, you deplete your glycogen stores and your protein synthesis (ability to build or repair muscle) is lowered and so your weight workout won't be so effective. Weights don't use up your glycogen stores or lower your protein synthesis like cardio does so if you do it before cardio, it won't have an impact on the cardio so much but it does the other way around. If that makes sense! The problem you could have though is that if you go all out on weights get heavy, exhausted legs and then try to run, it's not much fun! So I'd recommend seperating them out, which if you're doing things regularly is a good idea. Obviously if you go to the gym once a week, you have to combine them. It would mean you could do cardio at home say 3 times a week and strength 2 times a week. So maybe have Monday, Thurs and Sat as cardio days, Tuesdays and Fridays as your strength days and Weds and Sundays as rest days? Just a suggestion, need to find what works for you really.
Is it the best for me if I start NOW and keep doing it all the way through my weight loss so I have the best possible body/fitness by the time I've reached my goal?
Pretty much, yeah. If you start now, you'll be building muscle now as you're losing fat. You'll look more toned and healthy. And you'll have a higher metabolism and so you'll find the weight loss better.
I do have a gym membership but I never go, I guess I have to change that. I use to live 2 minutes from gym but now I'm 25 mins away so I get lazy and decide not to go. Bad habit I know, I have to change that and at least do my weights at gym.
Might as well use it if you already have it!
If I go to gym I will start taking protien shakes with me and drink one before and after gym, that will assist with my muscle building and also boost my calories. If I do a half hour weights session something like this, what sort of calories would I be burning? Just so I know how much extra I should eat.
No one can tell you that, at all. It would be an absolute guess. It depends on so many things like you height, weight, amount of muscle you already have, number of reps, type of weights, amount of weight, the intensity... it's just too variable to guess. If you really want to know the numbers then the only way is o get a heart rate monitor, one that has a chest strap. Tesco sells them for £20.
Lastly on calories, I am trying to stick to 1500 calories until I lose 30 pounds, I started at 297(135kg) so when I get to 264(120kg) I will boost to 1800 calories a day.
Is that a bad thing? Should I REALLY be sticking to at least 1800 a day regardless? Will I lose muscle mass if I'm going below that?
Can't really say to be honest, there isn't a magic number at all. What is right for me won't be right for someone else. It depends on your lifestyle as well as your general body make up like metabolism. But think of it this way, if you carry on at 1500 and hit a plateau, which happens quite often, where have you got to go from there? You really can't go down any further. The recommended amount for women is 1200 and I have 1350 so that when that happens, I can go down to boost it up a bit. Personally, I'd stick with one calorie amount, not change part way through unless it's because you need to because it's not working for you. Don't pick a lower number just because you want to get there faster, at the end of the day your health and well being is far more important than how long it takes you to lose the weight. You didn't put it all on overnight, neither did I, so we can't expect to lose it overnight either. You'll have to, as we all will, accept the fact that losing weight is a long and tedious journey sometimes but that it's worth it. Often the shortcuts that we take to try and speed things up don't end up helping but end up jeopardising everything we've worked so hard for.
So my advice, whether you choose to take it or not would be to up to 1800 calories, buy a heart rate monitor, use myfitnesspal.com to monitor your exercise calories and intake (don't just guess!), to incorporate strength training into your weekly regime and to make sure you have rest days!
I've gotta run, late for school so it's been a bit rushed. Hope it makes sense and helps!