Newbie in need of getting pregnancy weight off

Hi, I've gain 5 stone since getting pregnant with my youngest baba....so I'm desperately in need of getting back into my old clothes (nothing fits other than maternity clothes)......I'm gluten intolerant also....so this is a full on life change, not only to shift the extra lbs but eat good and feel good too. I cycled for 40 minutes last night on new exercise bike....first time in many years (plus I'm a lazy sod driving everything)....but the cycle made me feel so invigorated and I actually slept good too