Looking for motivation, support or friends! :)

I have been up and down with my weight continuously, I feel deflated! I am currently 161lbs, my height 5ft6inches. I ideal goal is 150lbs. I always get down to about 157lbs then I slip back and start gaining again! I'm really frustrated with myself as it's a constant battle! I attend my local gym 5-6 times a week when I'm committed and I participate in Zumba, Boxercise, Hiits, Spinning and cardio/weights in the gym. I really enjoy working out when I see the progress, body changes and muscle gain with tone and definition, then, I hit that plateau, everything collapses and I'm back to square one! My diet consists of fish, veg & fruit, no meat. I try to avoid dairy and gluten as I find my tummy swells when I consume these foods. I have yet to book an appointment to see if I have an intolerance. My life revolves around my kids and work, so my "me" time, is when I work out! Would love to hear from anyone experiencing the same challenges, anyone who can give constructive advice or anyone who would like to add me as a friend for motivation and support! Likewise if I can do the same I will! Thanks guys!