Am I more prone to gain a lot of weight because of this? And will I find it harder to lose. I'm eating healthy with the odd snack here and there I'm just very worried I'm going to get big again :(
You should not gain more than 3-6 pounds during pregnancy (some women lose weight!), the old wives tale "you're eating for two" is simply not true. You should not change your diet significantly with the exception of taking extra Folic Acid.
Be careful with the snacking, the extra weight will creep up on you, try snacking on something healthy, if it has fat, sugar or oils try to avoid it. I know that takes all the fun out of snacking as that pretty much covers all the things that taste like treats.
If there is a food that you enjoy that is healthy then treat yourself to that and avoid eating it at any other times as this will take away its "specialness".
Being pregnant does not make you an invalid and unless you are given a medical opinion that states otherwise you should continue to exercise, work and do everything you would normally do, this will also negate the effects of snacking.