Blackjack Loss with counting in Online Casino

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Dear all members,

I have been playing online blackjack in an online casino (prefer not to tell which one) in order to gain advantage based on casino new player welcome bonus.
I calculate based on the house edge (approximately 0.50%, 8-deck S17 DAS NHC no surrender) and I figured out that I have positive expectation in overall compared to the bonus offered.

I followed all basic strategy with minimum £5 bet all the time. I always hit 12 vs 3 in neutral count, never stand on 14-16 against high card in general (and bust most of the time), always double down soft hands vs weak upcards, double 10 against 9 in neutral to positive count, hit A7 vs face and never take any insurance in neutral deck. However, I also did card counting (although not much to gain due to potentially shallow penetration) and deviated some from basic strategy due to count (mostly standing on 16 vs 10 on positive count). The highest of my bet was just 4 betting units based on count. By the way since I have been playing for around 220 hands I faced many losses, as below according to the history I keep. I take a pause from game when true count dips to -2, some as -1.5.

			Avg Bet
Total Hands	220	100.00%	£6.14
Win	85	38.64%	£6.88
Lose	123	55.91%	£5.61
Push	12	5.45%	£6.25

I faced 10 losing sessions out off 15 sessions and I have already gone through just 20% of betting requirements. My bankroll history I keep track is attached here. The large sharp gain was a successful two double downs on both split hands at 3 bet size, but that was all gone. I'm new to card counting so I'm not sure this unlucky is general for card counters or not? In the late session I mostly flat bet all the time because the count was not in my favour to increase bet size. I feel somewhat desperate as the long way is ahead to complete betting requirement as now I feel unsecure as well though I need to keep making decisions like a robot all the time. May I ask experienced players is this normal and what should I do?