Stuck at 310 on GRE after 7 months of serious prep - Is 320+ still realistic?

Hi all,
I’ve been preparing seriously for the GRE for ~7 months with full time job and feel stuck. I’m a non-native English speaker, using English for 3-5 years professionally. No formal English education or test experience before, so my starting level must have been lower than 260.

Scores:
• Mocks (PPT 1/2/3): Q164/V157 → Q160/V158 → Q160/V155
• Official GREs (x2): ~Q158–160 / V150–152

Prep:
• Finished TTP GRE course
• GregMat “I Am Overwhelmed” plan (95%+ on foundations, 75% on hard quant)
• GregMat strategy series for both Quant and Verbal
• Memorized 30 vocab mountain groups

Challenges:
• Quant: Mostly careless/time-pressure mistakes
• Verbal: Not GRE vocab, but basic words (e.g., “pecking”, “bill”) throw me off; reading speed is an issue

Questions:
1. Is it realistic to push for a 320+ score given my background and current performance?
2. Should I invest in GregMat tutoring or some other service? I feel like I’m clearly doing something wrong, especially in quant. Looks like it’s my max performance in Verbal, but Quant supposed to be my spike…
3. Am I missing a technique, routine, or resource that helped you personally break out of a plateau?

Any advice is truly appreciated!

Check your foundation: see Taking the GRE for the first time - Shifting from the GMAT - #6 by Leaderboard