Whey protain is it makein me loose muscle?!

i have been going to gym now for about 9 months not using any protein powders i have gained muscle body looks better now always my biceps are rock hard and chest big as well.i went last week to buy a protein powder from holland and barret and purchased a whey protein call precision engineered whey cost ￡13.99 well since i have been using this i feel like iam loosing Weight a and muscles always feel like jelly why is this should i stop using this This is what it has Nutritional Information

Each(24g)serving contains:
Energy 398kJ and 94kcal
Protein 17.6g
Carbohydrate 1.7g
of which sugars 1.2g
Fat 1.9g
of which saturates 0.7g
Fibre 0.008g
Sodium 0.04g
100g contains:
Energy 1,668kJ and 395kcal
Protein 73.2g
Carbohydrate 7.3g
of which sugars 4.8g
Fat 8.1g
of which saturates 2.9g
Fibre 0.03g
Sodium 0.17g
Calcium 373mg
Magnesium 59mg
Phosphorus 371mg
Potassium 520mg
L-Alanine 3.2g
1L-Lysine 6.5g
L-Arginine 2.1g
1L-Methionine 1.5g
L-Aspartic Acid 8.1g
1L-Phenylalanine 2.3g
L-Cysteine 1.5g
L-Proline 4.1g
L-Glutamic Acid 10.2g
L-Serine 4.1g
L-Glycine 1.3g
1L-Threonine 5.5g
1L-Histidine 1.6g
1L-Tryptophan2 1.2g
1L-Isoleucine 4.2g
L-Tyrosine 2.2g
1L-Leucine 7.7g
1L-Valine 4.0g
1=Essential Amino Acids
2=L-Tryptophan is naturally occurring.