KNOWLEDGE Needed

Good morning anyone who is reading this. I'd really like to get some help and motivation with my fitness transformation and goals. If anyone has "knowledge" and not just opinions, I'd love to hear from you. My journey began 4 months ago when I decided that this year would be different. I was 5'7,165 lbs and totally out of shape. My original goal was to get down to 135. I've been 135 before and it was very bird-like on me. I cannot say I loved my body then, but I was happy to be skinny. In doing endless research, I figured out that weight wasn't near as important to me as the wasy my body looked to me. About a month and a half in I began weight training. So, the last month and a half my weightloss went from slowing down to pretty much a complete hault. I'm stuck at 150 and it's not budging. I've tried everything I know to do and now I'm reaching out. I don't necessarily want to get to 135, but I'd surely like to see the low 140's. I WILL NOT SACRIFICE MUSCLE TO ACHEIVE THIS GOAL. If anyone can lend me some knowledge, I'd greatly appreciate it. This is my routine.
Weights/Cardio
1 hr weight sessions Su, W, Th
HIIT sessions 20-30 minutes Su,W
Spin Class (1 hr) Sa
Spin 30 Mo
Friday OFF

Diet:
1500 cals p/day (1 cheat day every 2 weeks)
sample day:
Protein shake w/ 3 oz OJ
1/4 C. Steel cut oats w/ splenda and cinnamon
10 almonds, 1/2 light cheese stick
Grilled Chicken (3 oz) , green salad w/ beets and artichoke hearts, light dressing, brown rice (1/4 C)
yogurt w/ apples, cinnamon
protein bar
Grilled chicken or fish (3 oz) w/ 2 servings green vegatable
protein shake
3/4 GALLON OF WATER

stack:
Protein
BCAA's
Multi-Vitamin
EFA
D4 (fat burner) taken only when exhausted
Liquid collagen
Beta Alanine