Without knowing the exact amount of what you ate I can't say for sure, but looking at that I'm guessing you didn't eat enough carbs yesterday. On you high cal day you should be eating 300 grams of them at least that total about 1200 of your 3700 cals from carbs. Did you eat enough of them? Did you eat enough cals too? 3700? When making home made stuff make sure you weigh everything to make sure
If by fair bit to drink u mean alcohol, cut it out. I'm not saying you can't ever drink again, but while working at fat loss nutrition is king and let's say you consumed 600 cals of booze, that's 150 grams of carbs or protein you couldn't eat. Alcohol offers nowt nutritionally, stop it and start again once you've reached you goal.
Do your self a favour and stop weighing yourself all the time too, only weigh yourself immediately after your last meal on a high calorie day from now on. You've done one already, over the next one or twohigh cal days your weight will go up again, but buy the fourth it should start to fall. Assuming you'reburning enough/eating less calories on your low days.
You should be aiming for 1.5 pounds loss per week. Once you're losing about 1.5-1.7 pounds per week, keep going until you're onky losing one pound per week, then recalculate. Don't go over two pounds or it won't work.
Are you starting swimming?
Thanks for the reply @Blitzkrieg I'm afraid I can't dedicate myself to this at the moment. I can see it would take a considerable effort to stick rigidly to the programme. Unfortunately, that really isn't possible at the moment for a number of reasons. Same for the swimming.
But broadly, I will take the brakes off twice a week and see if that has any effect. I can do that much.
Yes you're right, fat loss or muscle gain without steroids is a 24/7 job.
Good luck