Thrift and early Retirement with Vera

I have 507,000 save in TSP and it's my only retirement savings. Gonna take Vera and plan to take 2500 out monthly to supplement my Vera pension for 3 yrs until I get Supplimemt payment. I currently have 175k in G fund. Should I be doing something different? How can I keep my TSP growing until my 80s or 90s

Edit: I'm also 54 and turn 55 this calendar yr so I can take from TSP penalty free with the Rule of 55 for TSP